
<!--
  ============================================================================
  (c) 2026 Accounting Arcade. All rights reserved.

  This software is the intellectual property of Accounting Arcade
  (accountingarcade.org). Unauthorized copying, modification, distribution,
  or reproduction of this file, in whole or in part, is strictly prohibited
  without prior written consent from Accounting Arcade.

  Licence: Single-institution use only. See licence agreement for full terms.
  Contact: david@accountingarcade.org
  ============================================================================

  ============================================================================
  CHAPTER 1 - GAME 1: "Business Entity Challenge"
  WAVE B PATHFINDER (rebuild 2026-07-27). Trinary tap-classify on TEACH-BEAT
  WAVES. Ruling: specs/joint_review_ch1-5_log.md row 1 (M - RATIFIED
  2026-07-19 + TEACH-BEAT WAVES).
  SCORM ID ACCT_ARCADE_CH1_GAME_01 - RENUMBERED 2026-08-03 under ruling A120,
  safe only because Chapter 1 has never been packaged (zero zips exist).
  ============================================================================

  WHAT THE REBUILD FIXES (spec game_1_spec.md sec.10, and the wave laws):

  1. sec.16.3-bis GRADE DECOUPLING. The only graded number is
     firstTryCorrect / session.rounds.length. The shipped build added a streak
     ladder to a score already scaled to 100 and clamped it, so 11 of 16
     correct reported 100%. There is no clamp on a graded expression here and
     no bonus term. displayPoints is HUD flavour, labelled "Points".
  2. sec.25 ANSWER KEY NOT BEATABLE. The DRAW is stratified GLOBALLY, not per
     wave: the 10 named taps are dealt 4/3/3 (which entity gets the extra tap
     is re-rolled every session) and the 3 finale taps are free except that
     they are never all one entity. A student who taps the same entity every
     round tops out at 6 of 13 = 46%, against a 60% pass mark. Because the
     three buttons carry fixed semantic labels, position and answer are the
     same strategy, so stratifying the draw covers both skews. Asserted at
     load by DRAW_AUDIT over 200 simulated sessions.
     ⚠ The two constraints that LOOK tidiest are the two that hand the game
     away, because ruling A19 reveals the correct answer after every tap:
     "one of each entity in the finale" makes the 3rd finale tap CERTAIN
     (measured 26.51% blind pass, 100% ceiling) and "the two taps in a wave
     must differ" measured 22.32%. The shipped shape measures 13.12%.
  3. O-2 ANSWER LEAK KILLED. Every pool item has step1.correctAnswer ===
     step2.correctAnswer, and the old selectProblems() then forced the round's
     two answers to DIFFER - a free 50/50 on half the graded taps. There are no
     two-step rounds now: one item, one question, one tap, and an item used
     once in a session is never drawn again in either form.
  4. sec.23 TAP-LOCK. answerLocked flips as the first statement of
     selectEntity(); the advance path uses a one-shot TOKEN minted by
     renderRound()/renderWaveCard() and consumed by the handler. The banned
     `advancedFromRound === currentRound` shape is not used.
  5. sec.12 FEEDBACK CONTRACT. Pre-game Ready card, accessible default-OFF
     toggle (role=switch, synced aria-checked, keyboard operable), wrong-only
     dock-bottom overlay with Your answer (red) / Correct answer (green) /
     explanation, scrollable body and pinned CONTINUE footer. A correct answer
     never opens the overlay.
  6. sec.2.3 PAGE-SCROLL. Unbounded #game-screen + sticky HUD; display is
     .active-scoped; .game-area carries min-height:0 and NO
     overflow-y / touch-action / overscroll-behavior.
  7. TEACH-BEAT WAVES (the ruling). Five named waves, each opening with one
     concept card then TWO scenario taps; a sixth MIXED wave of three taps
     with no card. Three entity storefronts grow as their cards are won.
     ⚠ joint_review_ch1-5_log.md row 1 (RATIFIED 2026-07-19) says "3-4
     scenario taps" per wave. Two is BELOW that row. Ruling A138 (David,
     2026-08-02) overrides it: the playtime cap is the newer ruling and the
     scenarios are the teaching, so the round count gives way, not the prose.
     13 graded rounds MEASURE 634 words = 4.88 min at 130 wpm (6.34 at 100).
  8. Learning page cut from 387 words to 128; the sentence naming three real
     corporations is gone; pinch-zoom re-enabled (O-15); the shipped
     build-template scaffold comment inside the pool array, and the duplicate
     id 1 it carried, are gone (O-7).
  ============================================================================
-->
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<head>
    <meta charset="UTF-8">
    <meta name="copyright" content="(c) 2026 Accounting Arcade. All rights reserved.">
    <meta name="author" content="David van Brecht, Accounting Arcade">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover, shrink-to-fit=no">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <meta name="mobile-web-app-capable" content="yes">
    <title>Business Entity Challenge - Chapter 1 Foundations</title>
    <link rel="preconnect" href="https://fonts.googleapis.com">
    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
    <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@600;700;800&family=Montserrat:wght@400;500;600;700&display=swap" rel="stylesheet">
    <style>
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

        :root {
            --font-heading: 'Poppins', system-ui, sans-serif;
            --font-body: 'Montserrat', system-ui, sans-serif;
            --bg-page: #F8FAFC;
            --bg-container: #FFFFFF;
            --border-color: #000000;
            --text-heading: #000000;
            --text-body: #1F2937;
            --btn-primary: #000000;
            --btn-hover: #2563EB;
            --color-success: #10B981;
            --color-error: #EF4444;
            --correct-green: #10B981;
            --wrong-red: #EF4444;
            --star-earned: #F59E0B;
            --star-empty: #CBD5E1;
            --entity-prop: #3B82F6;
            --entity-part: #10B981;
            --entity-corp: #8B5CF6;
        }

        html { -webkit-text-size-adjust: 100%; }

        body {
            font-family: var(--font-body);
            background-color: var(--bg-page);
            background-image: radial-gradient(#CBD5E1 1.5px, transparent 1.5px);
            background-size: 24px 24px;
            margin: 0;
            width: 100%;
            min-height: 100vh; min-height: 100dvh;
            overflow-x: hidden;
            color: var(--text-body);
        }

        .sr-only {
            position: absolute; width: 1px; height: 1px; padding: 0;
            margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); border: 0;
        }

        .btn {
            display: inline-flex; align-items: center; justify-content: center;
            padding: 12px 24px; min-height: 44px; min-width: 44px;
            background-color: var(--btn-primary); color: #FFFFFF;
            border: 3px solid var(--border-color); border-radius: 8px;
            font-family: var(--font-heading); font-weight: 700;
            text-transform: uppercase; box-shadow: 4px 4px 0px var(--border-color);
            cursor: pointer; transition: all 0.1s ease;
            font-size: 14px; letter-spacing: 1px;
        }
        .btn:hover { background-color: var(--btn-hover); }
        .btn:active { transform: translate(2px, 2px); box-shadow: 2px 2px 0px var(--border-color); }
        .btn-secondary { background-color: var(--bg-container); color: var(--text-heading); }

        .container, .card {
            background-color: var(--bg-container);
            border: 3px solid var(--border-color);
            border-radius: 8px; box-shadow: 8px 8px 0px var(--border-color);
            padding: 24px;
        }

        h1, h2, h3 { color: var(--text-heading); font-family: var(--font-heading); }

        .screen {
            display: none; width: 100%;
            min-height: 100vh; min-height: 100dvh;
            flex-direction: column;
        }
        .screen.active { display: flex; }

        .screen-content {
            flex: 1; padding: 20px; max-width: 900px; margin: 0 auto;
            width: 100%; position: relative; z-index: 2;
            min-height: 0;
            padding-bottom: calc(56px + env(safe-area-inset-bottom, 0px));
        }

        /* ===================== INTRO ===================== */
        #intro-screen {
            align-items: center; justify-content: center;
            background: linear-gradient(135deg, #0F766E, #22C55E, #86EFAC);
            background-size: 400% 400%;
            animation: gradientShift 14s ease infinite;
            position: relative; overflow: hidden; padding: 20px;
        }
        @keyframes gradientShift {
            0% { background-position: 0% 50%; }
            50% { background-position: 100% 50%; }
            100% { background-position: 0% 50%; }
        }
        @media (prefers-reduced-motion: reduce) { #intro-screen { animation: none; } }

        .intro-container {
            text-align: center; position: relative; z-index: 1;
            background: rgba(255, 255, 255, 0.96);
            border: 3px solid var(--border-color); border-radius: 16px;
            padding: 30px 24px; max-width: 520px; margin: 0 auto;
            box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
        }
        .intro-eyebrow {
            font-family: var(--font-heading); font-weight: 700; font-size: 0.85rem;
            letter-spacing: 0.18em; text-transform: uppercase;
            color: #0F766E; margin-bottom: 8px; overflow-wrap: anywhere;
        }
        .lo-line {
            font-size: 0.8rem; font-weight: 600; color: #4B5563;
            margin-bottom: 10px; overflow-wrap: anywhere;
        }
        /* sec.13b-bis width-safe landing badge: clamped tiles + wrap, never a fixed px */
        .intro-entity-badge {
            display: flex; justify-content: center; gap: 4px;
            margin: 14px 0; flex-wrap: wrap; max-width: 100%; min-width: 0;
        }
        .intro-entity-badge span {
            display: inline-flex; align-items: center; justify-content: center;
            width: clamp(26px, 8.5vw, 36px); height: clamp(26px, 8.5vw, 36px);
            background: #DCFCE7; border: 2px solid #16A34A; border-radius: 6px;
            font-family: var(--font-heading); font-weight: 800; color: #14532D;
            box-shadow: 3px 3px 0 #16A34A;
        }
        .game-title {
            font-family: var(--font-heading);
            font-size: clamp(1.8rem, 5vw, 2.5rem); font-weight: 800;
            color: #0F766E; line-height: 1.2; margin-bottom: 6px;
            overflow-wrap: anywhere;
        }
        .intro-subtitle { font-size: 0.95rem; color: var(--text-body); margin-bottom: 18px; line-height: 1.5; }
        .objective-box {
            background: linear-gradient(135deg, #DCFCE7, #BBF7D0);
            border: 2px solid #16A34A; border-radius: 12px;
            padding: 14px; margin-bottom: 14px; text-align: left;
        }
        .objective-box h3 { font-family: var(--font-heading); font-weight: 700; font-size: 1rem; margin: 0 0 6px 0; color: #14532D; }
        .objective-box p { margin: 0; color: #14532D; line-height: 1.5; }
        /* A206 (David, 2026-08-05) - the star rule, stated ONCE, before the student
           plays. A197's convention was only ever shown on the RESULTS screen, i.e.
           after the run that earned the stars. ⚠ WORDING IS AN A104 DRAFT.
           Kept deliberately SHORT and dense: this card already needs a scroll at
           375x667 (measured 2026-08-05 - START GAME sat 60px past the fold before
           this line existed), so every pixel added here is a pixel further from the
           button. Amber matches --star-earned; #78350F on #FFFBEB is a very high
           contrast pair, and the size floor is 0.78rem, the same as .lo-line. */
        .star-rule {
            font-size: 0.78rem; line-height: 1.4; text-align: left;
            color: #78350F; background: #FFFBEB;
            border: 2px solid var(--star-earned); border-radius: 10px;
            padding: 6px 10px; margin-bottom: 2px;
        }
        .intro-buttons { display: flex; flex-direction: column; gap: 12px; margin-top: 18px; }
        @media (min-width: 400px) { .intro-buttons { flex-direction: row; justify-content: center; } }

        /* ===================== LEARNING ===================== */
        #learning-screen { background: linear-gradient(180deg, #F0FDF4 0%, #BBF7D0 100%); }
        .learning-container {
            background: rgba(255, 255, 255, 0.98);
            border: 3px solid var(--border-color); border-radius: 16px;
            padding: 24px; max-width: 800px; margin: 20px auto;
            box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
        }
        .learning-content h2 {
            font-family: var(--font-heading); font-weight: 800; font-size: 1.5rem;
            margin-bottom: 16px; color: #0F766E; text-align: center;
            padding-bottom: 12px; border-bottom: 3px solid #16A34A;
        }
        .learning-content h3 { font-family: var(--font-heading); font-weight: 700; font-size: 1.05rem; color: #0F766E; margin: 16px 0 8px; }
        .learning-content p, .learning-content li { font-size: 0.95rem; line-height: 1.55; color: var(--text-body); }
        .term-chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
        .term-chip {
            background: #ECFDF5; border: 2px solid #16A34A; border-radius: 8px;
            padding: 8px 10px; font-size: 0.85rem; line-height: 1.35; color: #14532D; flex: 1 1 220px;
        }
        .term-chip strong { display: block; font-family: var(--font-heading); }
        .compare-wrap { overflow-x: auto; margin: 14px 0; }
        table.compare { border-collapse: collapse; width: 100%; min-width: 460px; font-size: 0.85rem; }
        table.compare th, table.compare td { border: 2px solid #16A34A; padding: 7px 9px; text-align: left; }
        table.compare th { background: #DCFCE7; font-family: var(--font-heading); color: #14532D; }
        .warmup-box {
            background: #FEF9C3; border: 2px dashed #CA8A04; border-radius: 10px;
            padding: 12px 14px; margin: 14px 0; font-size: 0.92rem; color: #713F12; line-height: 1.5;
        }

        /* ===================== READY CARD (sec.12.5) ===================== */
        #ready-screen { background: linear-gradient(180deg, #F0FDF4 0%, #DCFCE7 100%); align-items: center; justify-content: center; }
        .ready-card {
            background: var(--bg-container); border: 3px solid var(--border-color);
            border-radius: 16px; box-shadow: 8px 8px 0 var(--border-color);
            padding: 26px 22px; max-width: 480px; margin: 20px auto; text-align: center;
        }
        .ready-card h2 { font-family: var(--font-heading); font-size: 1.4rem; margin-bottom: 10px; }
        .ready-card p { font-size: 0.93rem; line-height: 1.55; margin-bottom: 8px; }
        .feedback-toggle-row {
            display: flex; align-items: center; justify-content: space-between;
            gap: 12px; margin: 18px 0 6px; padding-top: 16px;
            border-top: 2px solid #E2E8F0; text-align: left;
        }
        .feedback-toggle-label { font-size: 0.9rem; font-weight: 600; color: var(--text-body); }
        .toggle-switch {
            flex: 0 0 auto; width: 56px; height: 32px; border-radius: 999px;
            background: #CBD5E1; border: 3px solid var(--border-color);
            position: relative; cursor: pointer; transition: background-color 0.15s ease;
        }
        /* A3 / §12.4a tap target: the switch DRAWS 48x26 but must be TAPPABLE at
           44px. An inset-negative ::before enlarges the hit area without moving
           anything on screen — the shape already shipped in Ch1 G6. */
        .toggle-switch::before {
            content: ''; position: absolute; top: -9px; bottom: -9px; left: 0; right: 0;
        }
        .toggle-switch::after {
            content: ''; position: absolute; top: 2px; left: 2px;
            width: 22px; height: 22px; border-radius: 50%;
            background: #FFFFFF; border: 2px solid var(--border-color);
            transition: transform 0.15s ease;
        }
        .toggle-switch.on { background: var(--color-success); }
        .toggle-switch.on::after { transform: translateX(24px); }
        .toggle-switch:focus-visible { outline: 3px solid var(--btn-hover); outline-offset: 3px; }
        .toggle-note { font-size: 0.78rem; color: #64748B; text-align: left; }

        /* ===================== GAME SCREEN (sec.2.3 page-scroll) ===================== */
        /* Layout only on the bare id; `display` is .active-scoped below. */
        #game-screen {
            background-color: #052E1B;
            background-image: linear-gradient(rgba(134, 239, 172, 0.06) 1px, transparent 1px),
                              linear-gradient(90deg, rgba(134, 239, 172, 0.06) 1px, transparent 1px);
            background-size: 48px 48px;
            min-height: 100vh; min-height: 100dvh;
            flex-direction: column;
        }
        #game-screen.active { display: flex; }

        #game-screen .game-hud {
            display: flex; justify-content: space-between; align-items: center;
            padding: 10px 116px 10px 20px;   /* sec.2.4: >=116px right clearance for the fixed controls */
            background: #064E3B; border-bottom: 2px solid #34D399;
            flex-shrink: 0; position: sticky; top: 0; z-index: 50;
            flex-wrap: wrap; gap: 10px; min-height: 64px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
        }
        #game-screen .hud-item { text-align: center; }
        #game-screen .hud-label { font-size: 12px; text-transform: uppercase; opacity: 0.9; color: #A7F3D0; letter-spacing: 0.5px; }
        #game-screen .hud-value { font-weight: 700; font-size: 18px; color: #6EE7B7; font-family: var(--font-heading); font-variant-numeric: tabular-nums; }
        #game-screen #round-display { min-width: 5ch; }
        #game-screen #score-display { min-width: 4ch; }
        #game-screen .hud-item.hud-hint-anchor {
            position: absolute; right: 8px; top: 50%; transform: translateY(-50%); margin: 0; padding: 0;
        }
        #game-screen .btn { background-color: #34D399; border-color: #34D399; color: #052E1B; }
        #game-screen .btn:hover { background-color: #6EE7B7; border-color: #6EE7B7; color: #052E1B; }
        #game-screen .btn-secondary { background: transparent; color: #A7F3D0; border-color: #A7F3D0; }

        /* sec.2.3 page-scroll model: NO overflow-y / touch-action / overscroll-behavior here. */
        .game-area {
            flex: 1 0 auto; display: flex; flex-direction: column;
            align-items: center; justify-content: flex-start;
            min-height: 0; width: 100%;
            padding: 20px; padding-bottom: calc(72px + env(safe-area-inset-bottom, 0px));
        }
        .game-area > * { flex-shrink: 0; }

        .hint-btn-hud {
            width: 44px; height: 44px; border-radius: 50%;
            border: 2px solid #34D399; background: #FFFFFF; cursor: pointer;
            font-size: 18px; display: flex; align-items: center; justify-content: center;
            color: #047857; padding: 0; line-height: 1;
        }
        .hint-btn-hud:hover { background: #ECFDF5; }
        .hint-bubble {
            display: none; margin: 14px 0 0; background: #ECFDF5; border: 2px solid #047857;
            border-radius: 8px; padding: 10px 14px; font-size: 0.95rem; color: #064E3B; text-align: left;
        }
        .hint-bubble.active { display: block; }

        /* ---- storefront strip: the ruled visual payoff ---- */
        .storefronts {
            display: flex; gap: 10px; width: 100%; max-width: 720px;
            margin-bottom: 18px; justify-content: center; flex-wrap: wrap;
        }
        .storefront {
            flex: 1 1 150px; min-width: 96px;
            background: #064E3B; border: 2px solid #065F46; border-radius: 10px;
            padding: 10px 8px; text-align: center; color: #D1FAE5;
            transition: border-color 200ms ease, box-shadow 200ms ease;
        }
        .storefront .sf-build {
            font-size: 22px; line-height: 1.15; letter-spacing: 1px;
            min-height: 26px; overflow-wrap: anywhere;
        }
        .storefront .sf-name { font-family: var(--font-heading); font-weight: 700; font-size: 12px; margin-top: 5px; overflow-wrap: anywhere; }
        .storefront .sf-count { font-size: 11px; opacity: 0.85; font-variant-numeric: tabular-nums; }
        .storefront.sf-prop { border-color: var(--entity-prop); }
        .storefront.sf-part { border-color: var(--entity-part); }
        .storefront.sf-corp { border-color: var(--entity-corp); }
        .storefront.grew { animation: sfGrow 520ms ease-out; box-shadow: 0 0 18px rgba(110, 231, 183, 0.45); }
        @keyframes sfGrow { 0% { transform: scale(1); } 45% { transform: scale(1.09); } 100% { transform: scale(1); } }
        @media (prefers-reduced-motion: reduce) { .storefront.grew { animation: none; } }

        /* ---- wave concept card (the teach beat) ---- */
        .wave-card {
            width: 100%; max-width: 720px;
            background: #FFFFFF; border: 3px solid #34D399; border-radius: 14px;
            padding: 20px 18px; color: #052E1B; text-align: left;
        }
        .wave-card .wave-eyebrow {
            font-family: var(--font-heading); font-size: 12px; font-weight: 800;
            letter-spacing: 0.14em; text-transform: uppercase; color: #047857; margin-bottom: 6px;
        }
        .wave-card h3 { font-family: var(--font-heading); font-size: 1.25rem; margin-bottom: 10px; overflow-wrap: anywhere; }
        .wave-card .wave-lead { font-size: 0.95rem; line-height: 1.5; margin-bottom: 12px; }
        .wave-rows { display: flex; flex-direction: column; gap: 8px; }
        .wave-row {
            display: flex; gap: 10px; align-items: flex-start;
            border: 2px solid #A7F3D0; border-radius: 10px; padding: 9px 11px; background: #F0FDF4;
        }
        .wave-row .wr-tag {
            font-family: var(--font-heading); font-weight: 800; font-size: 12px;
            flex: 0 0 auto; padding: 3px 7px; border-radius: 6px; color: #FFFFFF;
        }
        .wave-row.wr-prop .wr-tag { background: var(--entity-prop); }
        .wave-row.wr-part .wr-tag { background: var(--entity-part); }
        .wave-row.wr-corp .wr-tag { background: var(--entity-corp); }
        .wave-row .wr-text { font-size: 0.9rem; line-height: 1.45; overflow-wrap: anywhere; }
        .wave-takeaway {
            margin-top: 12px; background: #ECFDF5; border-left: 5px solid #047857;
            border-radius: 8px; padding: 10px 12px; font-size: 0.9rem; line-height: 1.45;
        }
        .wave-card-footer { margin-top: 16px; text-align: center; }

        /* ---- question + entity buttons ---- */
        .question-card {
            background: #064E3B; border: 3px solid #34D399; border-radius: 12px;
            padding: 24px 20px; margin-bottom: 20px; text-align: center;
            width: 100%; max-width: 720px;
        }
        .question-eyebrow {
            font-family: var(--font-heading); font-size: 12px; font-weight: 700;
            letter-spacing: 0.14em; text-transform: uppercase; color: #A7F3D0; margin-bottom: 10px;
            overflow-wrap: anywhere;
        }
        .question-avatar { font-size: 34px; line-height: 1; margin-bottom: 8px; }
        .question-text {
            font-size: 19px; font-weight: 700; line-height: 1.5; color: #FFFFFF;
            font-family: var(--font-heading); overflow-wrap: anywhere;
        }
        .player-response { display: flex; flex-direction: column; align-items: center; width: 100%; flex-shrink: 0; }
        .entity-buttons { display: flex; flex-direction: column; gap: 12px; width: 100%; max-width: 560px; }
        @media (min-width: 720px) {
            .entity-buttons { flex-direction: row; flex-wrap: wrap; justify-content: center; max-width: 760px; }
            .entity-btn { flex: 1 1 220px; }
        }
        /* sec.3.y: text-bearing tiles auto-height with a min-height floor, never a fixed height. */
        .entity-btn {
            padding: 15px 16px; min-height: 62px; width: 100%;
            border: 3px solid #34D399; border-radius: 10px; cursor: pointer;
            background: rgba(52, 211, 153, 0.08); color: #ECFDF5;
            font-family: var(--font-heading); font-weight: 700; font-size: 16px;
            line-height: 1.3; text-align: center; overflow-wrap: anywhere;
            transition: all 0.15s ease;
        }
        .entity-btn .eb-sub { display: block; font-family: var(--font-body); font-weight: 500; font-size: 12px; opacity: 0.85; margin-top: 3px; }
        .entity-btn.eb-prop { border-color: var(--entity-prop); }
        .entity-btn.eb-part { border-color: var(--entity-part); }
        .entity-btn.eb-corp { border-color: var(--entity-corp); }
        .entity-btn:hover { background: rgba(52, 211, 153, 0.22); }
        .entity-btn:active { transform: scale(0.98); }
        .entity-btn.correct {
            background: #34D399 !important; border-color: #34D399 !important; color: #052E1B !important;
            box-shadow: 0 0 22px rgba(52, 211, 153, 0.5) !important; animation: pulseWin 0.45s ease;
        }
        .entity-btn.incorrect {
            background: #F87171 !important; border-color: #F87171 !important; color: #450A0A !important;
            box-shadow: 0 0 22px rgba(248, 113, 113, 0.5) !important; animation: shake 0.3s ease;
        }
        @keyframes pulseWin { 0% { transform: scale(1); } 50% { transform: scale(1.05); } 100% { transform: scale(1); } }
        @keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-8px); } 75% { transform: translateX(8px); } }
        @media (prefers-reduced-motion: reduce) { .entity-btn.correct, .entity-btn.incorrect { animation: none; } }

        .streak-indicator {
            display: flex; visibility: hidden; align-items: center; gap: 5px;
            background: linear-gradient(135deg, #34D399, #A7F3D0);
            padding: 6px 14px; border-radius: 20px; color: #052E1B;
            font-weight: 700; font-size: 14px; font-family: var(--font-heading);
            font-variant-numeric: tabular-nums;
        }
        .streak-indicator #streak-count { min-width: 2ch; text-align: center; }
        .streak-indicator.active { visibility: visible; }

        /* ===================== sec.12.3.1 DOCK-BOTTOM WRONG-FEEDBACK ===================== */
        .wrong-feedback-overlay {
            position: fixed; left: 0; right: 0; bottom: 0; top: auto;
            background: transparent; display: none;
            justify-content: center; align-items: flex-end;
            padding: 8px; padding-bottom: calc(8px + env(safe-area-inset-bottom, 0px));
            pointer-events: none; z-index: 1200;
        }
        .wrong-feedback-overlay.active { display: flex; }
        .wrong-feedback-card {
            pointer-events: auto; display: flex; flex-direction: column;
            max-height: 45vh; width: min(560px, 100%);
            background: #FFFFFF; border: 3px solid var(--wrong-red); border-radius: 12px;
            box-shadow: 0 -8px 24px rgba(0, 0, 0, 0.35); overflow: hidden;
        }
        .wrong-feedback-header {
            flex: 0 0 auto; padding: 12px 18px; background: #FEE2E2; color: #991B1B;
            font-family: var(--font-heading); font-weight: 800; font-size: 17px;
        }
        .wrong-feedback-body {
            flex: 1 1 auto; overflow-y: auto; -webkit-overflow-scrolling: touch;
            padding: 14px 18px; color: var(--text-body); text-align: left;
        }
        .wrong-feedback-footer {
            flex: 0 0 auto; position: sticky; bottom: 0; background: #FFFFFF;
            border-top: 2px solid #E2E8F0; padding: 12px 18px; text-align: center;
        }
        .feedback-your-answer, .feedback-correct-answer { display: flex; gap: 8px; margin-bottom: 8px; font-size: 0.95rem; }
        .feedback-label { font-weight: 700; opacity: 0.8; }
        .feedback-value { font-weight: 600; }
        .feedback-wrong { color: var(--wrong-red, #EF4444); }
        .feedback-right { color: var(--correct-green, #10B981); }
        .feedback-explanation { margin-top: 8px; line-height: 1.5; }

        /* ===================== MUTE / FOOTER / RESULTS ===================== */
        .mute-btn {
            position: fixed; top: calc(12px + env(safe-area-inset-top, 0px)); right: 12px;
            z-index: 9999; background: rgba(0, 0, 0, 0.35);
            border: 2px solid rgba(255, 255, 255, 0.6); color: #FFFFFF;
            width: 44px; height: 44px; min-width: 44px; border-radius: 50%;
            font-size: 20px; cursor: pointer; display: flex;
            align-items: center; justify-content: center; padding: 0;
            -webkit-tap-highlight-color: transparent;
        }
        .mute-btn.muted { background: rgba(239, 68, 68, 0.55); border-color: #EF4444; }
        /* sec.18.14: in game the sticky HUD owns the top-right; the mute button seats BELOW it. */
        body.in-game .mute-btn { top: calc(var(--hud-h, 64px) + 8px); right: 8px; }

        .results-container { text-align: center; }
        .results-title { font-family: var(--font-heading); font-size: 28px; font-weight: 800; margin-bottom: 10px; }
        .results-score { font-family: var(--font-heading); font-size: 68px; font-weight: 800; color: #0F766E; margin: 16px 0; }
        .results-stars { margin: 16px 0; }
        .results-stars .star { color: var(--star-empty); font-size: 46px; margin: 0 5px; }
        .results-stars .star.earned { color: var(--star-earned); text-shadow: 0 0 20px rgba(245, 158, 11, 0.5); }
        .results-message { font-size: 19px; margin: 16px 0; }
        .results-stats { display: flex; justify-content: center; gap: 36px; margin: 26px 0; flex-wrap: wrap; }
        .stat-item { text-align: center; }
        .stat-value { font-size: 24px; font-weight: 700; font-variant-numeric: tabular-nums; }
        .stat-label { font-size: 14px; color: var(--text-body); }
        .display-only-note { font-size: 12px; color: #64748B; margin-top: 4px; }

        @media (max-height: 900px) {
            .game-area { padding: 12px; padding-bottom: calc(80px + env(safe-area-inset-bottom, 0px)); }
            #game-screen .game-hud { padding: 8px 116px 8px 15px; }
        }
        @media (max-height: 700px) {
            .game-area { padding: 8px; padding-bottom: calc(80px + env(safe-area-inset-bottom, 0px)); }
            #game-screen .game-hud { padding: 6px 116px 6px 10px; gap: 5px; }
            .question-card { padding: 16px 13px; margin-bottom: 14px; }
            .question-text { font-size: 17px; }
            .entity-btn { padding: 12px 13px; font-size: 15px; min-height: 54px; }
            .storefronts { margin-bottom: 12px; }
        }

        /* ============ EXIT CONFIRMATION (A307, David 2026-08-12) ============
           Sized for 375px (David's iPhone renders 375, NOT 414) and for 768px
           portrait (students use tablets, and 768-1024 portrait is ordinary).
           `justify-content: center` WITH `margin: auto` on the box is the safe
           centring pair: plain centring on a flex column CLIPS the top of an
           over-tall box with no way to scroll to it, and this box grows with the
           longer of the two messages.
           ⚠ AUTHORED AGAINST THIS FILE, NOT COPIED. Two things differ from the
           CH5-G41 reference: this game has no --theme-shadow / --accent-2 custom
           property (its containers cast their shadow in --border-color), and its
           .copyright-footer is POSITION:FIXED across the whole app rather than
           in-flow inside each section, so the bottom padding has to clear it the
           way .screen-content does at l.165. */
        #exit-screen {
            background: var(--bg-page);
            align-items: center; justify-content: center;
            padding: 20px;
            padding-top: calc(20px + env(safe-area-inset-top, 0px));
            padding-bottom: calc(56px + env(safe-area-inset-bottom, 0px));
            overflow-y: auto;
        }
        .exit-container {
            text-align: center;
            background: var(--bg-container);
            border: 3px solid var(--border-color);
            border-radius: 8px;
            box-shadow: 8px 8px 0px var(--border-color);
            padding: 24px 20px;
            max-width: 480px; width: 100%;
            margin: auto;
        }
        .exit-mark { font-size: 40px; line-height: 1; color: var(--color-success); margin-bottom: 10px; }
        .exit-title {
            font-family: var(--font-heading); font-weight: 800;
            font-size: clamp(20px, 5vw, 26px);
            color: var(--text-heading); line-height: 1.25;
        }
        .exit-title:focus { outline: none; }
        .exit-body { margin-top: 14px; font-size: 16px; line-height: 1.6; color: var(--text-body); }
        .exit-body p { margin-bottom: 10px; }
        .exit-body p:last-child { margin-bottom: 0; }
        .exit-body .exit-lead {
            font-family: var(--font-heading); font-weight: 700;
            font-size: 18px; color: #0F766E;   /* this file's own accent - see .results-score */
        }

        .copyright-footer {
            position: fixed; bottom: 0; left: 0; width: 100%; text-align: center;
            padding: 4px 10px; padding-bottom: calc(8px + env(safe-area-inset-bottom, 0px));
            font-family: var(--font-body); font-size: 11px; color: #94A3B8;
            background: rgba(255, 255, 255, 0.95); border-top: 1px solid #E2E8F0;
            z-index: 9999; letter-spacing: 0.3px;
            pointer-events: none;
        }
        .copyright-footer a { color: #94A3B8; text-decoration: none; }
    </style>
</head>

<body>
    <div id="app">
        <button id="mute-btn" class="mute-btn" data-action="toggle-mute" aria-label="Toggle sound">&#128266;</button>

        <!-- ===================== INTRO (sec.13b two buttons, sec.13c name only) ===================== -->
        <div id="intro-screen" class="screen active">
            <div class="intro-container">
                <div class="intro-eyebrow">Chapter 1 &mdash; Foundations &amp; The Accounting Equation</div>
                <h1 class="game-title">Business Entity Challenge</h1>
                <div class="lo-line">Learning Outcome Covered: 1.1c</div>
                <div class="intro-entity-badge" aria-hidden="true">
                    <span>E</span><span>N</span><span>T</span><span>I</span><span>T</span><span>Y</span>
                </div>
                <p class="intro-subtitle">One owner, several owners, or a company of its own? Grow three storefronts by placing each business in the right form.</p>

                <div class="objective-box">
                    <h3>&#127919; Objective</h3>
                    <p>Five short waves, one for each thing the choice decides: owners, debts, tax, starting up and lifetime. Every wave opens with a concept card, then three business stories to place. The last wave mixes all five with no card.</p>
                </div>

                <!-- A206: the star rule. SIGNED AS WRITTEN by David 2026-08-29 - do not reword per game. -->
                <div class="star-rule">&#11088; <strong>How stars work:</strong> more stars = a better result. 3 stars = no mistakes at all.</div>

                <div class="intro-buttons">
                    <button class="btn btn-secondary" data-action="show-learning">&#128214; LEARNING PAGE</button>
                    <button class="btn" data-action="show-ready">&#9654;&#65039; START GAME</button>
                </div>
            </div>
        </div>

        <!-- ===================== LEARNING PAGE - HARD CAP 200 WORDS ===================== -->
        <div id="learning-screen" class="screen">
            <div class="screen-content">
                <div class="learning-container">
                    <button class="btn btn-secondary" data-action="show-intro" style="margin-bottom:18px">&#8592; BACK</button>
                    <div class="learning-content" id="learning-content">
                        <h2>&#128218; Three Ways to Own a Business</h2>

                        <div class="term-chips">
                            <div class="term-chip"><strong>Proprietorship</strong>One owner, no separate company.</div>
                            <div class="term-chip"><strong>Partnership</strong>Two or more owners sharing one business.</div>
                            <div class="term-chip"><strong>Corporation</strong>A company that is legally its own person.</div>
                            <div class="term-chip"><strong>Liability</strong>Who has to pay the debts.</div>
                        </div>

                        <div class="compare-wrap">
                            <table class="compare">
                                <tr><th>Decides</th><th>Proprietorship</th><th>Partnership</th><th>Corporation</th></tr>
                                <tr><td>Owners</td><td>1</td><td>2 or more</td><td>Shareholders</td></tr>
                                <tr><td>Debts</td><td>Unlimited</td><td>Unlimited</td><td>Limited</td></tr>
                                <tr><td>Tax</td><td>Owner pays</td><td>Partners pay</td><td>Company pays</td></tr>
                                <tr><td>Starting</td><td>Just begin</td><td>Written agreement</td><td>State filing</td></tr>
                                <tr><td>Lifetime</td><td>Ends with owner</td><td>Ends if a partner goes</td><td>Continues</td></tr>
                            </table>
                        </div>

                        <p><strong>Unlimited</strong> means your house and car can be taken to pay business debts. <strong>Limited</strong> means you lose only what you put in.</p>

                        <div class="warmup-box" id="warmup-box">
                            <strong>Warm-up:</strong> Nadia repairs bicycles alone in her garage and keeps every dollar of profit. That is a proprietorship. Not graded.
                        </div>

                        <h3>How to Play</h3>
                        <p>Read the story, then tap the entity it describes.</p>
                    </div>
                    <button class="btn" data-action="show-ready" style="margin-top:18px;display:block;margin-left:auto;margin-right:auto">&#9654;&#65039; START GAME</button>
                </div>
            </div>
        </div>

        <!-- ===================== READY CARD (sec.12.5 non-arcade toggle home) ===================== -->
        <div id="ready-screen" class="screen">
            <div class="screen-content" style="display:flex;align-items:center;justify-content:center;">
                <div class="ready-card">
                    <h2>Ready?</h2>
                    <p>Thirteen business stories across six waves. No clock &mdash; read as slowly as you like.</p>
                    <p>Your grade is simply how many you get right first time.</p>

                    <div class="feedback-toggle-row">
                        <span class="feedback-toggle-label" id="feedback-toggle-label">Show feedback on wrong answers</span>
                        <div class="toggle-switch" id="feedback-toggle" data-action="toggle-feedback"
                             role="switch" aria-checked="false" tabindex="0"
                             aria-labelledby="feedback-toggle-label"
                             aria-label="Show feedback after each wrong answer"></div>
                    </div>
                    <p class="toggle-note">When this is on, a wrong answer explains itself before you move on.</p>

                    <div style="display:flex;flex-direction:column;gap:12px;align-items:center;margin-top:20px;">
                        <button class="btn" data-action="start-game">&#9654;&#65039; START ROUND 1</button>
                        <button class="btn btn-secondary" data-action="show-intro">&#8592; BACK</button>
                    </div>
                </div>
            </div>
        </div>

        <!-- ===================== GAME SCREEN ===================== -->
        <div id="game-screen" class="screen">
            <div class="game-hud">
                <div class="hud-item">
                    <div class="hud-label">Points</div>
                    <div class="hud-value" id="score-display">0</div>
                </div>
                <div class="hud-item">
                    <div class="hud-label" id="round-label">Round</div>
                    <div class="hud-value" id="round-display">1/13</div>
                </div>
                <div class="hud-item">
                    <div class="streak-indicator" id="streak-indicator"><span>&#128293;</span><span id="streak-count">0</span></div>
                </div>
                <div class="hud-item hud-hint-anchor">
                    <button class="hint-btn-hud" data-action="show-hint" aria-label="Show hint" title="Hint">&#128161;</button>
                </div>
            </div>
            <div class="game-area" id="game-area"></div>
        </div>

        <!-- ===================== RESULTS ===================== -->
        <div id="results-screen" class="screen">
            <div class="screen-content">
                <div class="container results-container">
                    <h1 class="results-title">&#127942; Game Complete!</h1>
                    <div class="results-score" id="final-score">0%</div>
                    <div class="results-stars">
                        <span class="star" id="star-1">&#9734;</span><span class="star" id="star-2">&#9734;</span><span class="star" id="star-3">&#9734;</span>
                    </div>
                    <p class="results-message" id="results-message">Keep practicing!</p>
                    <div id="pass-status" style="font-size:22px;font-weight:bold;margin:20px 0;padding:15px;border-radius:8px;">PASSED</div>
                    <div class="results-stats">
                        <div class="stat-item">
                            <div class="stat-value" id="correct-count">0</div>
                            <div class="stat-label">First-try correct</div>
                            <div class="display-only-note">This is your grade</div>
                        </div>
                        <div class="stat-item">
                            <div class="stat-value" id="points-total">0</div>
                            <div class="stat-label">Arcade points</div>
                            <div class="display-only-note">Fun only &mdash; not graded</div>
                        </div>
                    </div>
                    <div style="display:flex;flex-direction:column;gap:12px;align-items:center;margin-top:20px;">
                        <button class="btn" data-action="play-again">&#128260; PLAY AGAIN</button>
                        <button class="btn btn-secondary" data-action="exit" style="min-width:200px;">EXIT TO COURSE</button>
                    </div>
                </div>
            </div>
        </div>

        <!-- ===================== EXIT CONFIRMATION (A307, David 2026-08-12) =====================
             Shown after the score is saved and the session is closed, because
             window.close() is blocked in a same-tab LMS embed (Moodle) and the
             student was left pressing a button that appeared to do nothing.
             showExitConfirmation() fills #exit-body; the two versions of the
             message live there, not here, because the wording depends on whether a
             score was actually sent. -->
        <div id="exit-screen" class="screen" aria-labelledby="exit-title">
            <div class="exit-container" role="status" aria-live="polite">
                <div class="exit-mark" aria-hidden="true">&#10004;</div>
                <h1 class="exit-title" id="exit-title" tabindex="-1">You can close this page</h1>
                <div class="exit-body" id="exit-body"></div>
            </div>
        </div>
    </div>

    <!-- sec.12.3.1 dock-bottom wrong-answer overlay: scrollable body, pinned footer -->
    <div class="wrong-feedback-overlay" id="wrong-feedback-overlay" role="dialog" aria-modal="false" aria-labelledby="wrong-feedback-header">
        <div class="wrong-feedback-card">
            <div class="wrong-feedback-header" id="wrong-feedback-header">Not quite!</div>
            <div class="wrong-feedback-body">
                <div class="feedback-your-answer">
                    <span class="feedback-label">Your answer:</span>
                    <span class="feedback-value feedback-wrong" id="your-answer-text"></span>
                </div>
                <div class="feedback-correct-answer">
                    <span class="feedback-label">Correct answer:</span>
                    <span class="feedback-value feedback-right" id="correct-answer-text"></span>
                </div>
                <div class="feedback-explanation" id="explanation-text"></div>
            </div>
            <div class="wrong-feedback-footer">
                <button class="btn" id="wrong-feedback-continue" data-action="dismiss-feedback" data-token="0">CONTINUE</button>
            </div>
        </div>
    </div>

    <div class="copyright-footer">
        &copy; 2026 <a href="https://accountingarcade.org" tabindex="-1" aria-hidden="true">Accounting Arcade</a>. All rights reserved.
    </div>

    <script>
        /* A78-geo (2026-09-13): the CONTINUE ghost tap.
           A student answers, taps CONTINUE, and the finger bounces. The second contact lands
           where CONTINUE was -- and the next round has already painted a graded control under
           that exact point, so the game marks a question the student never read.
           measured at 375x667: the ghost ran selectEntity and recordAnswer after the GOT IT wave card; BOTH dismiss doors advance a round, so both arm
           ⛔ NARROW BY DESIGN. Only a contact within ADVANCE_GHOST_R px of the CONTINUE
           contact point is refused, and only for ADVANCE_GHOST_MS after it. Every other
           control on the new round grades instantly -- a student answering fast is never
           slowed. That is the whole difference from the blunt entry shield.
           It is a DEADLINE, not a callback, so it can never stick.
           The contact point comes from a capture-phase recorder on `document`, which runs
           before every handler however that handler is bound.
           ⛔ NEVER armed by a keyboard press, a scripted click, or an advance a TIMER
           started -- a correct answer that advances 600 ms later leaves lastTapAt stale.
           Fail-open: an advance that cannot be attributed to a finger is simply not shielded.
           ⛔ Navigation is never shielded: CONTINUE, hint, mute, PLAY AGAIN and EXIT all run
           normally. A second tap on CONTINUE itself is already inert. */
        const ADVANCE_GHOST_MS = 500;       // window, measured from the first contact
        const ADVANCE_GHOST_R = 32;         // CSS px half-side — one fingertip of jitter
        const ADVANCE_GHOST_ARM_MS = 120;   // older than this and the tap did not cause this advance
        let lastTapX = 0, lastTapY = 0, lastTapAt = 0, lastTapSeq = 0, lastTapReal = false;
        document.addEventListener('click', function (ev) {
            lastTapReal = ev.detail > 0 && isFinite(ev.clientX) && isFinite(ev.clientY);
            lastTapX = ev.clientX; lastTapY = ev.clientY;
            lastTapAt = Date.now(); lastTapSeq++;
        }, true);
        let advanceGhostUntil = 0, advanceGhostX = 0, advanceGhostY = 0, advanceGhostSeq = -1;
        function armAdvanceGhostShield() {
            if (!lastTapReal) return;
            if (Date.now() - lastTapAt > ADVANCE_GHOST_ARM_MS) return;
            advanceGhostX = lastTapX; advanceGhostY = lastTapY;
            advanceGhostSeq = lastTapSeq;
            advanceGhostUntil = lastTapAt + ADVANCE_GHOST_MS;
        }
        function advanceGhostShielded() {
            if (advanceGhostUntil <= Date.now()) return false;
            if (lastTapSeq === advanceGhostSeq) return false;   // no NEW contact since the advance
            if (!lastTapReal) return false;                     // keyboard, or no tap at all
            return Math.abs(lastTapX - advanceGhostX) <= ADVANCE_GHOST_R
                && Math.abs(lastTapY - advanceGhostY) <= ADVANCE_GHOST_R;
        }

        /* ====================================================================
           CH1 G1 - Business Entity Challenge. Wave B pathfinder.
           GRADED  : firstTryCorrect / session.rounds.length  (the ONLY number
                     that reaches the student's percentage, the stars, the pass
                     banner and SCORM). No bonus term, no clamp.
           DISPLAY : displayPoints, currentStreak, storefront levels.
           LOCKS   : answerLocked (answer surface) + a one-shot advance TOKEN.
           ==================================================================== */

        /* MATCHES imsmanifest.xml. Chapter-scoped under ruling A120 (2026-08-03), done
           while Ch1 has ZERO packages: once one ships, changing this imports as a NEW
           LMS course (scorm-id-collision-audit). On the root element so the id is read. */
        const SCORM_ID = "ACCT_ARCADE_CH1_GAME_01";
        document.documentElement.dataset.scormId = SCORM_ID;

        const ENTITIES = ["Proprietorship", "Partnership", "Corporation"];
        const ENTITY_META = {
            "Proprietorship": { cls: "prop", icon: "\uD83D\uDC64", sub: "One owner", build: "\uD83C\uDFE0" },
            "Partnership":    { cls: "part", icon: "\uD83D\uDC65", sub: "Two or more owners", build: "\uD83C\uDFEA" },
            "Corporation":    { cls: "corp", icon: "\uD83C\uDFE2", sub: "A separate company", build: "\uD83C\uDFE2" }
        };

        /* A138 (David, 2026-08-02): 5 waves x 2 named taps + a 3-tap finale = 13.
           David's standing three-minute rule (david-three-minute-playtime-rule) caps
           playtime, and he accepted ~4.4 min here rather than cut the scenario prose,
           because the scenarios ARE the teaching.
           ⚠ RE-MEASURED at 13 rounds by driving the real page and word-counting what
           is actually painted (concept-card bodies + the question text of every
           round, one consistent rule on both surfaces): 634 words, so 4.88 min at
           130 wpm - NOT the 4.4 min the ruling assumed, and 6.34 min at the 100 wpm
           an ESL reader is likelier to manage. The floor is the FIVE CONCEPT CARDS:
           340 of those 634 words, fixed whatever the round count. Cutting rounds can
           only ever touch the other 294. (20 rounds measured 789 words / 6.07 min on
           the same instrument.) Changing any of these three numbers changes
           the graded denominator, the stratification and both load-time audits -
           they are all DERIVED from these three below, never hand-scaled. */
        const TAPS_PER_NAMED_WAVE = 2;
        const FINALE_TAPS = 3;
        const TOTAL_GRADED = 13;         /* 5 named waves x 2 + 3 finale - asserted in POOL_AUDIT */
        const PASS_MARK = 60;
        const POINTS_PER_ROUND = 10;     /* DISPLAY ONLY */

        /* --------------------------------------------------------------------
           TEACH-BEAT WAVES (ruling: joint_review_ch1-5_log.md row 1).
           Each named wave opens with ONE concept card, then TAPS_PER_NAMED_WAVE
           scenario taps drawn from that wave's pool category (A138: two, cut from
           three for the playtime cap). The finale has no card.
           The card teaches the RULE; the taps require applying it to a story,
           so the card cannot answer any item for the student.
           -------------------------------------------------------------------- */
        const WAVES = [
            { key: "ownership", name: "Who Owns It?",
              lead: "The first question is simply how many owners there are, and who gets to decide.",
              rows: { "Proprietorship": "One owner. That person decides everything and keeps all the profit.",
                      "Partnership": "Two or more owners. They share the decisions and share the profit.",
                      "Corporation": "Shareholders own it and elect a board to run it. There can be one or thousands." },
              takeaway: "Count the owners first. If ownership is held in shares, it is a corporation." },
            { key: "liability", name: "Who Pays the Debts?",
              lead: "If the business cannot pay, whose money is at risk?",
              rows: { "Proprietorship": "Unlimited. The owner's house, car and savings can be taken.",
                      "Partnership": "Unlimited. Every partner is personally responsible for the whole debt.",
                      "Corporation": "Limited. Shareholders lose only what they invested." },
              takeaway: "Personal property at risk means unlimited liability. Personal property protected means a corporation." },
            { key: "taxation", name: "Who Pays the Tax?",
              lead: "Business profit is taxed once, or twice, depending on the form.",
              rows: { "Proprietorship": "The profit goes on the owner's own tax return. One return, no business tax.",
                      "Partnership": "Profit passes through. Each partner reports their share on their own return.",
                      "Corporation": "The company files and pays its own tax, and shareholders are taxed again on dividends." },
              takeaway: "If the business itself pays tax, it is a corporation. Otherwise the owners pay." },
            { key: "formation", name: "How Do You Start It?",
              lead: "Some businesses exist the moment you begin. Others do not exist until a government says so.",
              rows: { "Proprietorship": "Just start trading. No filing, no fee, lowest set-up cost.",
                      "Partnership": "Start trading together, but write an agreement covering shares and duties.",
                      "Corporation": "File articles of incorporation with the state, adopt bylaws, appoint a board." },
              takeaway: "Paperwork filed with the state means a corporation. A written agreement between owners means a partnership." },
            { key: "lifetime", name: "How Long Does It Last?",
              lead: "Does the business end when a person does?",
              rows: { "Proprietorship": "Limited life. It ends when the owner retires, stops or dies.",
                      "Partnership": "Limited life. It can end when a partner leaves or dies.",
                      "Corporation": "Perpetual. It carries on no matter who owns the shares." },
              takeaway: "If the business survives its owners, it is a corporation." }
        ];

        /* --------------------------------------------------------------------
           A138 STRATIFICATION SHAPE - DERIVED, never hand-scaled.
           10 named taps over 3 entities cannot be even. The honest shape is
           4 / 3 / 3, and WHICH entity gets the extra tap is re-rolled every
           session, so no entity is systematically over-represented and the
           round-number reader (sec.25-quater class 6) stays flat.
           These four lines re-derive themselves if TAPS_PER_NAMED_WAVE ever
           changes again: base = floor(10/3) = 3, extra = 10 mod 3 = 1 entity
           gets base+1 = 4. WAVES must already be declared (const TDZ).
           -------------------------------------------------------------------- */
        const NAMED_TAPS = WAVES.length * TAPS_PER_NAMED_WAVE;                 /* 10 */
        const NAMED_BASE = Math.floor(NAMED_TAPS / ENTITIES.length);           /*  3 */
        const NAMED_EXTRA = NAMED_TAPS % ENTITIES.length;                      /*  1 entity gets one more */
        const NAMED_MAX_PER_ENTITY = NAMED_BASE + (NAMED_EXTRA > 0 ? 1 : 0);   /*  4 */

        /* --------------------------------------------------------------------
           sec.25-quater CLASS 5 (family-identifier): THE DISPLAYED AVATAR MUST
           CARRY NO INFORMATION ABOUT THE ANSWER.

           The authored per-item avatar did. Measured over the 100-item pool:
           only the two business-suit glyphs ever sit on a Corporation item, so
           12 of the 14 authored avatars RULED CORPORATION OUT before a word was
           read, and 5 of them were deterministic (one answer class only). On its
           own that reader passed 56.8% of sessions; combined with the wave-quota
           elimination it passed 94.6% (06b's exact enumeration: 97.96%).

           So the glyph shown is drawn from this roster by ROUND POSITION plus a
           per-session offset - a function of the round index alone, provably
           independent of the answer key. All eight are the gender-neutral
           person-plus-role forms, so they never contradict the character's name.

           WARNING: step2.avatar is retained as authored data and is DELIBERATELY
           NOT READ by the renderer. Do not "restore" it - it is the tell.
           -------------------------------------------------------------------- */
        const AVATAR_ROSTER = [
            "\uD83E\uDDD1\u200D\uD83D\uDCBC",   /* office worker */
            "\uD83E\uDDD1\u200D\uD83C\uDF73",   /* cook          */
            "\uD83E\uDDD1\u200D\uD83C\uDFA8",   /* artist        */
            "\uD83E\uDDD1\u200D\uD83D\uDD27",   /* mechanic      */
            "\uD83E\uDDD1\u200D\uD83C\uDF3E",   /* farmer        */
            "\uD83E\uDDD1\u200D\uD83D\uDCBB",   /* technologist  */
            "\uD83E\uDDD1\u200D\uD83C\uDFEB",   /* teacher       */
            "\uD83E\uDDD1\u200D\uD83D\uDD2C"    /* scientist     */
        ];
        let avatarOffset = 0;   /* re-rolled once per session, never per round */

        /* --------------------------------------------------------------------
           sec.25-quater CLASS 5, SECOND CHANNEL — THE CHARACTER NAME.
           Not named by the 2026-07-27 06b gate, and worse than the avatar once
           it is combined with elimination. The pool's 20 first names appear five
           times each and are answer-skewed (Mike 4/5 Proprietorship, Tom 4/5
           Partnership); a reader who memorises that table and combines it with
           the quota passed 99.55% of sessions on the shipped build.

           So the name on screen is recast too: every cast name in the rendered
           text is swapped for a roster name of the SAME gender class, indexed by
           ROUND POSITION plus a per-session offset. Gender is preserved because
           87 of the 100 scenarios carry a gendered pronoun that would otherwise
           contradict the new name — and gender itself is NOT a channel (measured
           40% / 42% argmax over the pool, i.e. chance).
           -------------------------------------------------------------------- */
        const CAST_M = ["Bob", "Carlos", "Chris", "David", "James", "John", "Kevin", "Mike", "Steve", "Tom"];
        const CAST_F = ["Amy", "Anna", "Emma", "Jenny", "Laura", "Lisa", "Maria", "Nicole", "Rachel", "Sara"];
        const NAME_ROSTER_M = ["Arun", "Ben", "Diego", "Hiro", "Luca", "Marco", "Omar", "Pavel", "Samir", "Tobias"];
        const NAME_ROSTER_F = ["Aisha", "Bea", "Chiara", "Dalia", "Elif", "Ines", "Mei", "Priya", "Rosa", "Zara"];
        const CAST = {};
        CAST_M.forEach(function (n, i) { CAST[n] = { roster: NAME_ROSTER_M, index: i }; });
        CAST_F.forEach(function (n, i) { CAST[n] = { roster: NAME_ROSTER_F, index: i }; });
        const CAST_RE = new RegExp('\\b(' + CAST_M.concat(CAST_F).join('|') + ')\\b', 'g');
        let nameOffset = 0;     /* re-rolled once per session */

        /* Two different cast names in one item land on two different roster
           names, because their fixed indices differ and the roster is as long as
           the cast. Across sessions the offset makes the mapping uniform, so a
           name learned by replaying carries no information about the answer. */
        function recastNames(text, roundIndex) {
            return String(text).replace(CAST_RE, function (m) {
                const c = CAST[m];
                if (!c) return m;
                return c.roster[(roundIndex + nameOffset + c.index) % c.roster.length];
            });
        }

        /* The learning-page warm-up. Asserted DISJOINT from every graded item so a
           teach beat can never leak a graded answer. */
        const DEMO_SCENARIO = "Nadia repairs bicycles alone in her garage and keeps every dollar of profit.";
        const DEMO_NAME = "Nadia";

        /* ====================================================================
           MASTER POOL - 100 items, carried over verbatim from the shipped build.
           Schema: { id, category, step1{question,correctAnswer,explanation},
                     step2{scenario,avatar,characterName,correctAnswer,explanation} }
           ==================================================================== */
        const MASTER_PROBLEM_POOL = [
            { id: 1, category: "liability",
              step1: { question: "Which business type protects owners from losing personal assets if the business fails?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations provide limited liability protection. Owners can only lose what they invested in the business, not their personal property." },
              step2: { scenario: "Bob wants to start a manufacturing business but is worried about lawsuits. He wants to make sure his house and personal savings are protected if the business gets sued.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Bob",
                       correctAnswer: "Corporation",
                       explanation: "A corporation is best for Bob because it provides limited liability, protecting his personal assets like his house and savings from business debts and lawsuits." } },
            { id: 2, category: "liability",
              step1: { question: "In which business type can the owner lose personal property to pay business debts?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the owner has unlimited liability. This means personal assets like a house or car can be used to pay business debts." },
              step2: { scenario: "Maria runs a small cleaning service by herself. She is wondering if her personal car could be taken to pay her business debts if the business cannot pay its bills.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Maria",
                       correctAnswer: "Proprietorship",
                       explanation: "Maria has a proprietorship, which means she has unlimited liability. Her personal car and other assets could be at risk if the business cannot pay its debts." } },
            { id: 3, category: "liability",
              step1: { question: "Which business type means shareholders can only lose the money they invested?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, shareholders have limited liability. They can only lose the money they invested to buy shares, not their personal assets." },
              step2: { scenario: "John wants to invest in a technology company. He wants to make sure that if the company fails, he will only lose his investment and not his personal savings account.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "John",
                       correctAnswer: "Corporation",
                       explanation: "John should invest in a corporation because shareholders have limited liability. He can only lose his investment, not his personal savings." } },
            { id: 4, category: "liability",
              step1: { question: "In which business type are multiple owners personally responsible for all business debts?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, all partners have unlimited liability. Each partner is personally responsible for the full amount of all business debts." },
              step2: { scenario: "Lisa and her friend Tom started a catering business together. Lisa is worried because Tom made some bad purchases. She is wondering if she could lose her personal savings because of his decisions.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Lisa",
                       correctAnswer: "Partnership",
                       explanation: "Lisa and Tom have a partnership, which means both have unlimited liability. Lisa could be held responsible for all business debts, even those caused by Tom." } },
            { id: 5, category: "liability",
              step1: { question: "Which business type offers limited liability, meaning owners cannot lose personal possessions?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations offer limited liability protection. The personal possessions of shareholders are protected from business debts and lawsuits." },
              step2: { scenario: "Sara is starting a construction company. Construction businesses face many risks and potential lawsuits. She wants to protect her family home from any business problems.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Sara",
                       correctAnswer: "Corporation",
                       explanation: "A corporation would protect Sara's family home because it provides limited liability. Her personal assets are separate from the business." } },
            { id: 6, category: "liability",
              step1: { question: "The business owner has unlimited liability and can lose personal assets in a what type of entity?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship offers no separation between the owner and the business. The owner has unlimited liability and personal assets are at risk." },
              step2: { scenario: "Mike owns a small repair shop by himself. A customer is suing him for damage to their equipment. Mike is worried that he might lose his personal truck to pay for the lawsuit.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udd27", characterName: "Mike",
                       correctAnswer: "Proprietorship",
                       explanation: "Mike has a proprietorship with unlimited liability. His personal truck and other assets could be taken to pay for the lawsuit if he loses." } },
            { id: 7, category: "liability",
              step1: { question: "Which business type provides a legal shield between business debts and personal assets?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation is a separate legal entity that provides a shield between business debts and the personal assets of its shareholders." },
              step2: { scenario: "Anna wants to start a delivery service. She has heard that delivery companies get sued frequently. She wants a legal barrier between her business and her personal belongings.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Anna",
                       correctAnswer: "Corporation",
                       explanation: "A corporation creates a legal barrier between Anna's business and personal assets. This limited liability protection keeps her belongings safe." } },
            { id: 8, category: "liability",
              step1: { question: "In which business type does each partner risk their personal wealth for business debts?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, each partner has unlimited liability. All partners risk their personal wealth to cover business debts." },
              step2: { scenario: "David and his brother started a landscaping company together. They are both concerned that if the business fails, they could each lose their personal cars and savings.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf3e", characterName: "David",
                       correctAnswer: "Partnership",
                       explanation: "David and his brother have a partnership with unlimited liability. Both of them risk their personal assets, including cars and savings, if the business fails." } },
            { id: 9, category: "liability",
              step1: { question: "Personal assets are protected from business lawsuits in which type of business?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, shareholders have limited liability. Their personal assets are protected from business lawsuits." },
              step2: { scenario: "Emma is opening a medical equipment store. She knows that product liability lawsuits are common in this industry. She wants to keep her personal home separate from any business lawsuits.",
                       avatar: "\ud83d\udc69\u200d\u2695\ufe0f", characterName: "Emma",
                       correctAnswer: "Corporation",
                       explanation: "A corporation would protect Emma's home because it provides limited liability. Her personal assets are legally separate from the business." } },
            { id: 10, category: "liability",
              step1: { question: "Which business type means the single owner is fully responsible for all debts?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, there is one owner who is fully responsible for all business debts. There is no separation between personal and business liability." },
              step2: { scenario: "Carlos runs a food truck by himself. He owes money to several suppliers. He is worried that if the food truck business fails, he will have to pay all the debts from his personal bank account.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf73", characterName: "Carlos",
                       correctAnswer: "Proprietorship",
                       explanation: "Carlos has a proprietorship, so he is personally responsible for all business debts. His personal bank account could be used to pay suppliers." } },
            { id: 11, category: "liability",
              step1: { question: "Which type of business provides the strongest protection for personal property?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations provide the strongest protection for personal property through limited liability. Shareholders are protected from business debts." },
              step2: { scenario: "Jenny is starting a chemical cleaning business. This type of business has many potential hazards and liability risks. She wants the strongest possible protection for her family's savings.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udd2c", characterName: "Jenny",
                       correctAnswer: "Corporation",
                       explanation: "A corporation offers Jenny the strongest liability protection. Her family's savings would be protected even if the business faces lawsuits." } },
            { id: 12, category: "liability",
              step1: { question: "In which business type could partners lose their house to pay business debts?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, all partners have unlimited liability. Partners could lose personal assets like their house to pay business debts." },
              step2: { scenario: "Kevin and his cousin opened a printing shop together. Kevin is nervous because the business borrowed a lot of money. He wonders if his house could be taken if the business cannot repay the loans.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Kevin",
                       correctAnswer: "Partnership",
                       explanation: "Kevin has a partnership with unlimited liability. His house could potentially be at risk if the business cannot repay its loans." } },
            { id: 13, category: "liability",
              step1: { question: "Which business type keeps the owner's personal savings separate from business risks?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation keeps personal savings separate from business risks. Shareholders have limited liability and only risk their investment." },
              step2: { scenario: "Rachel wants to open a pet grooming business. She has worked hard to save money for retirement. She wants to make sure her retirement savings are completely separate from any business problems.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Rachel",
                       correctAnswer: "Corporation",
                       explanation: "A corporation would keep Rachel's retirement savings separate from the business. Limited liability means her personal savings are protected." } },
            { id: 14, category: "liability",
              step1: { question: "The owner risks all personal assets in which type of one-person business?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the single owner risks all personal assets. There is no legal separation between the owner and the business." },
              step2: { scenario: "Steve owns a small tutoring business by himself. He recently borrowed money to buy computers. He is wondering if he could lose his car if he cannot repay the business loan.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfeb", characterName: "Steve",
                       correctAnswer: "Proprietorship",
                       explanation: "Steve has a proprietorship with unlimited liability. His car and other personal assets could be at risk if he cannot repay the business loan." } },
            { id: 15, category: "liability",
              step1: { question: "Which business type allows investors to invest money without risking personal assets?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, investors buy shares and have limited liability. They can invest without risking their personal assets beyond the investment." },
              step2: { scenario: "Nicole wants to invest some of her savings in a friend's business. She wants to help her friend but does not want to risk losing her house if the business fails.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Nicole",
                       correctAnswer: "Corporation",
                       explanation: "Nicole should invest in a corporation. As a shareholder, she would have limited liability and only risk the money she invests, not her house." } },
            { id: 16, category: "liability",
              step1: { question: "Multiple owners can be held personally responsible for all debts in which business type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, both owners have unlimited liability. Each partner can be held fully responsible for all business debts." },
              step2: { scenario: "Amy and her sister opened a flower shop together. The shop owes money to several vendors. Amy is concerned that she alone could be forced to pay all the debts if her sister cannot contribute.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Amy",
                       correctAnswer: "Partnership",
                       explanation: "Amy and her sister have a partnership. Each partner has unlimited liability and can be held fully responsible for all debts." } },
            { id: 17, category: "liability",
              step1: { question: "Which business type protects shareholders from paying business debts with personal money?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation protects shareholders from using personal money to pay company debts. Shareholders have limited liability." },
              step2: { scenario: "James is thinking about buying shares in a software company. He wants to be sure that if the company goes bankrupt, he will not have to pay the company's debts from his personal accounts.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbb", characterName: "James",
                       correctAnswer: "Corporation",
                       explanation: "As a shareholder in a corporation, James has limited liability. If the company goes bankrupt, he will not have to pay debts from his personal accounts." } },
            { id: 18, category: "liability",
              step1: { question: "The sole owner has unlimited liability for all business obligations in a what?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the sole owner has unlimited liability. The owner is personally responsible for all business obligations." },
              step2: { scenario: "Laura runs a yoga studio by herself. She recently signed a long term lease for the studio space. She is wondering who is responsible if the business cannot pay the rent.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Laura",
                       correctAnswer: "Proprietorship",
                       explanation: "Laura has a proprietorship with unlimited liability. She is personally responsible for the rent even if her yoga business cannot pay." } },
            { id: 19, category: "liability",
              step1: { question: "Which business entity separates personal wealth from business liabilities?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation is a separate legal entity that keeps personal wealth separate from business liabilities. Shareholders have limited liability." },
              step2: { scenario: "Chris is launching an online retail store. He has significant personal investments that he has built over the years. He wants to make sure his personal investments are completely separate from any business liabilities.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbb", characterName: "Chris",
                       correctAnswer: "Corporation",
                       explanation: "A corporation would keep Chris's personal investments separate from business liabilities. The limited liability protects his personal wealth." } },
            { id: 20, category: "liability",
              step1: { question: "In which business type are co-owners jointly and personally liable for debts?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, all co-owners are jointly and personally liable for business debts. Each partner shares unlimited liability." },
              step2: { scenario: "Tom and his best friend started an event planning company together. They take on many large events with significant expenses. Tom is worried about what happens if one event causes major financial losses.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Tom",
                       correctAnswer: "Partnership",
                       explanation: "Tom and his friend have a partnership with unlimited liability. Both are jointly liable for any financial losses the business experiences." } },
            { id: 21, category: "ownership",
              step1: { question: "Which business type has only one owner who makes all decisions?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship has a single owner who has complete control over all business decisions." },
              step2: { scenario: "Carlos wants to be his own boss and make all business decisions himself. He does not want to share control with anyone else or answer to a board of directors.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Carlos",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship is perfect for Carlos because he will be the only owner and can make all decisions without sharing control." } },
            { id: 22, category: "ownership",
              step1: { question: "In which business type do two or more people share ownership and control?",
                       correctAnswer: "Partnership",
                       explanation: "A partnership is owned by two or more people who share control and make decisions together." },
              step2: { scenario: "Jenny and her best friend want to open a bakery together. They plan to split the work and share in making all important decisions.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udf73", characterName: "Jenny",
                       correctAnswer: "Partnership",
                       explanation: "A partnership allows Jenny and her friend to share ownership and make decisions together as equal partners." } },
            { id: 23, category: "ownership",
              step1: { question: "Which business type has shareholders who elect a board of directors?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, shareholders own the company and elect a board of directors to make major decisions." },
              step2: { scenario: "Steve wants to start a company that can have many owners and a formal leadership structure. He wants the owners to vote on who leads the company.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Steve",
                       correctAnswer: "Corporation",
                       explanation: "A corporation allows Steve to have many shareholders who can vote to elect a board of directors to lead the company." } },
            { id: 24, category: "ownership",
              step1: { question: "One person owns everything and keeps all profits in which business type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, one person owns everything and keeps all the profits without sharing with anyone." },
              step2: { scenario: "Rachel runs a small photography business. She does all the work herself and wants to keep every dollar of profit she makes without splitting it with anyone.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Rachel",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship means Rachel owns everything and keeps all profits. She does not have to share with partners or shareholders." } },
            { id: 25, category: "ownership",
              step1: { question: "Which business type allows partners to combine their skills and resources?",
                       correctAnswer: "Partnership",
                       explanation: "A partnership allows two or more people to combine their different skills, knowledge, and resources to run a business together." },
              step2: { scenario: "Kevin is great at cooking but not good with numbers. His cousin Lisa is an accountant. They want to open a restaurant together and combine their different skills.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf73", characterName: "Kevin",
                       correctAnswer: "Partnership",
                       explanation: "A partnership is ideal for Kevin and Lisa to combine their skills. Kevin handles cooking while Lisa manages the finances." } },
            { id: 26, category: "ownership",
              step1: { question: "Which business type can sell shares to raise money from many investors?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation can sell shares of stock to raise money from many different investors who become part owners." },
              step2: { scenario: "Nicole wants to start a technology company that will need lots of money to grow. She wants to be able to sell small pieces of ownership to many different investors.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbb", characterName: "Nicole",
                       correctAnswer: "Corporation",
                       explanation: "A corporation allows Nicole to sell shares to many investors. This is the best way to raise large amounts of money from multiple people." } },
            { id: 27, category: "ownership",
              step1: { question: "The owner has complete control without sharing power in which business type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the single owner has complete control over all aspects of the business without sharing power." },
              step2: { scenario: "James wants to start a consulting business. He prefers to work alone and make every decision himself without having to consult with partners or a board.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "James",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship gives James complete control. He can make all decisions without consulting anyone else." } },
            { id: 28, category: "ownership",
              step1: { question: "Profits must be divided among multiple owners in which business type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, profits and losses are divided among all partners according to their agreement." },
              step2: { scenario: "Amy and two of her friends started a tutoring business together. They agreed to split all profits equally among the three of them.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfeb", characterName: "Amy",
                       correctAnswer: "Partnership",
                       explanation: "Amy and her friends have a partnership where profits are shared. Their agreement determines how to divide the money." } },
            { id: 29, category: "ownership",
              step1: { question: "Which business type separates ownership from day to day management?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, shareholders own the company but the board of directors and managers run the daily operations." },
              step2: { scenario: "Chris wants to invest in a company but does not want to manage it every day. He prefers to own part of the company while professional managers handle operations.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Chris",
                       correctAnswer: "Corporation",
                       explanation: "A corporation separates ownership from management. Chris can own shares without being involved in daily operations." } },
            { id: 30, category: "ownership",
              step1: { question: "One person makes all business decisions alone in which type of entity?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the single owner makes all business decisions independently without needing approval from others." },
              step2: { scenario: "Laura wants to open a flower shop. She wants to decide everything herself including store hours, prices, and which flowers to sell without asking anyone else.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Laura",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship allows Laura to make all decisions alone. She does not need approval from partners or a board." } },
            { id: 31, category: "ownership",
              step1: { question: "Which business type requires co-owners to agree on major decisions?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, major decisions usually require agreement among the partners since they share control." },
              step2: { scenario: "David and his brother want to expand their lawn care business. They need to discuss and agree together before making big purchases or hiring new employees.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf3e", characterName: "David",
                       correctAnswer: "Partnership",
                       explanation: "David and his brother have a partnership where major decisions require both of them to agree." } },
            { id: 32, category: "ownership",
              step1: { question: "Which business type allows ownership to be easily transferred by selling shares?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, ownership is represented by shares that can be easily bought and sold without affecting the business." },
              step2: { scenario: "Emma wants to start a company where investors can easily sell their ownership stake to other people whenever they want.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Emma",
                       correctAnswer: "Corporation",
                       explanation: "A corporation allows easy transfer of ownership through shares. Investors can sell their shares to others without disrupting the business." } },
            { id: 33, category: "ownership",
              step1: { question: "The single owner bears all responsibilities in which business type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the single owner bears all responsibilities for running the business and making it successful." },
              step2: { scenario: "Mike runs a car detailing service by himself. He handles everything from finding customers to doing the work to managing the money.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udd27", characterName: "Mike",
                       correctAnswer: "Proprietorship",
                       explanation: "Mike has a proprietorship where he is responsible for everything. There are no partners or shareholders to share the work." } },
            { id: 34, category: "ownership",
              step1: { question: "Two friends sharing control of a business would form which entity type?",
                       correctAnswer: "Partnership",
                       explanation: "When two friends share ownership and control of a business together, they form a partnership." },
              step2: { scenario: "Tom and his friend Sara want to start a coffee shop together. They will both invest money and share control over running the business.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf73", characterName: "Tom",
                       correctAnswer: "Partnership",
                       explanation: "Tom and Sara would form a partnership to share ownership and control of the coffee shop together." } },
            { id: 35, category: "ownership",
              step1: { question: "Which business type has a formal board that makes major company decisions?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation has a formal board of directors elected by shareholders to make major decisions for the company." },
              step2: { scenario: "Maria wants her company to have a formal structure with a group of experienced leaders making strategic decisions for the business.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Maria",
                       correctAnswer: "Corporation",
                       explanation: "A corporation has a board of directors that provides formal governance and makes major strategic decisions." } },
            { id: 36, category: "ownership",
              step1: { question: "Which business type gives one person full authority over operations?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship gives the single owner full authority over all business operations and decisions." },
              step2: { scenario: "Bob wants to start a home repair business. He wants complete authority to decide which jobs to take, what to charge, and how to do the work.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udd27", characterName: "Bob",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship gives Bob full authority over his home repair business. He makes all operational decisions himself." } },
            { id: 37, category: "ownership",
              step1: { question: "In which business type do all owners have a voice in running the company?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, all partners typically have a voice in running the company and participating in decisions." },
              step2: { scenario: "Anna and her two sisters want to start an event planning business. Each sister wants to have a say in how the business is run.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Anna",
                       correctAnswer: "Partnership",
                       explanation: "A partnership allows Anna and her sisters to all have a voice in running the business and making decisions together." } },
            { id: 38, category: "ownership",
              step1: { question: "Which business type can have thousands of owners through stock ownership?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation can have thousands of shareholders who own stock, each owning a small piece of the company." },
              step2: { scenario: "Lisa dreams of building a company that grows so large it has thousands of investors all over the world owning pieces of it.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Lisa",
                       correctAnswer: "Corporation",
                       explanation: "A corporation can have thousands of shareholders worldwide. Large companies like this sell shares on stock exchanges." } },
            { id: 39, category: "ownership",
              step1: { question: "The owner works alone without partners in which type of business?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, there is only one owner who works without partners or other shareholders." },
              step2: { scenario: "John wants to start a freelance writing business. He plans to work completely alone without any business partners or employees.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbb", characterName: "John",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship is ideal for John's freelance business. He works alone without partners or co-owners." } },
            { id: 40, category: "ownership",
              step1: { question: "Decision making is shared between multiple owners in which business type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, decision making is shared between the partners who jointly control the business." },
              step2: { scenario: "Sara and her husband want to open an art gallery together. They want to make all business decisions together as a team.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Sara",
                       correctAnswer: "Partnership",
                       explanation: "A partnership allows Sara and her husband to share decision making. They can run the art gallery together as equal partners." } },
            { id: 41, category: "taxation",
              step1: { question: "Which business type pays its own separate corporate taxes?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation is a separate legal entity that files and pays its own corporate taxes, separate from its shareholders." },
              step2: { scenario: "Bob started a large manufacturing company. His accountant told him that the business must file its own tax return and pay corporate income tax.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Bob",
                       correctAnswer: "Corporation",
                       explanation: "Bob's corporation must file and pay its own taxes. The business is taxed separately from the shareholders." } },
            { id: 42, category: "taxation",
              step1: { question: "Business income goes on the owner's personal tax return in which type of entity?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, all business income is reported on the owner's personal tax return. There is no separate business tax filing." },
              step2: { scenario: "Maria runs a small tutoring business by herself. At tax time, she reports all her business income on her personal tax return using a special schedule.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Maria",
                       correctAnswer: "Proprietorship",
                       explanation: "Maria has a proprietorship, so she reports business income on her personal return. The business is not taxed separately." } },
            { id: 43, category: "taxation",
              step1: { question: "Which business type might face double taxation on profits?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations may face double taxation. The company pays corporate tax on profits, then shareholders pay personal tax on dividends." },
              step2: { scenario: "John's company pays corporate taxes on its profits. When the company pays dividends to shareholders, they also pay taxes on those dividends.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "John",
                       correctAnswer: "Corporation",
                       explanation: "John's corporation faces double taxation. The company pays corporate tax, then shareholders pay personal tax on dividends." } },
            { id: 44, category: "taxation",
              step1: { question: "Each partner reports their share of income on personal tax returns in which business type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, profits pass through to partners who each report their share on their personal tax returns." },
              step2: { scenario: "Lisa and her partner Tom run a catering business together. Each of them reports their share of the profits on their own personal tax returns.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Lisa",
                       correctAnswer: "Partnership",
                       explanation: "Lisa and Tom have a partnership with pass-through taxation. Each partner reports their share on personal returns." } },
            { id: 45, category: "taxation",
              step1: { question: "Which business type has the simplest tax filing for a one-person business?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship has the simplest taxes. The owner just adds a schedule to their personal tax return with no separate business return." },
              step2: { scenario: "Sara wants to start a small online selling business. She wants the easiest possible tax situation with no separate business tax forms to file.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Sara",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship offers Sara the simplest taxes. She reports business income on her personal return with no separate filing." } },
            { id: 46, category: "taxation",
              step1: { question: "The business files a corporate tax return separately from owners in which entity?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation files its own corporate tax return separately from the personal returns of its shareholders." },
              step2: { scenario: "Mike's company has its own tax identification number and files a corporate tax return every year, completely separate from Mike's personal taxes.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Mike",
                       correctAnswer: "Corporation",
                       explanation: "Mike's corporation files separate corporate taxes. The business has its own tax identity apart from shareholders." } },
            { id: 47, category: "taxation",
              step1: { question: "Pass-through taxation means income goes directly to owners in which business type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, pass-through taxation means business income goes directly to the owner's personal tax return." },
              step2: { scenario: "Anna runs a freelance design business by herself. All her business earnings pass through directly to her personal income for tax purposes.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Anna",
                       correctAnswer: "Proprietorship",
                       explanation: "Anna has a proprietorship with pass-through taxation. Her business income flows directly to her personal taxes." } },
            { id: 48, category: "taxation",
              step1: { question: "Which business type requires the most complex tax filing with separate returns?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations have the most complex taxes because they must file separate corporate tax returns in addition to shareholder personal returns." },
              step2: { scenario: "David's company needs to hire an accountant to handle all the complex corporate tax forms. The business has many tax requirements beyond what shareholders file.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "David",
                       correctAnswer: "Corporation",
                       explanation: "David's corporation has complex tax requirements including separate corporate returns, which requires professional accountants." } },
            { id: 49, category: "taxation",
              step1: { question: "Business profits are taxed only once on the co-owners' personal returns in which entity type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, profits are taxed only once when partners report their share on personal returns. There is no business level tax." },
              step2: { scenario: "Emma and her sister run a bakery together. The bakery does not pay business taxes. Instead, each sister pays personal taxes on their share of profits.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udf73", characterName: "Emma",
                       correctAnswer: "Partnership",
                       explanation: "Emma's partnership avoids double taxation. Profits are only taxed once when partners report them on personal returns." } },
            { id: 50, category: "taxation",
              step1: { question: "The sole owner reports all business income on their personal return in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the sole owner reports all business income on their personal tax return using the appropriate schedule." },
              step2: { scenario: "Carlos runs a food truck by himself. At tax time, he adds all his food truck income to his personal tax return. There is no separate business tax filing.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf73", characterName: "Carlos",
                       correctAnswer: "Proprietorship",
                       explanation: "Carlos has a proprietorship and reports all business income on his personal return. The business is not taxed separately." } },
            { id: 51, category: "taxation",
              step1: { question: "Which business type can retain earnings without distributing to owners?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation can keep profits in the business as retained earnings without distributing them to shareholders." },
              step2: { scenario: "Jenny's business wants to save money for future expansion. The board decides to keep profits in the business rather than paying dividends to shareholders.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Jenny",
                       correctAnswer: "Corporation",
                       explanation: "Jenny's corporation can retain earnings in the business. Shareholders are not taxed until dividends are actually paid." } },
            { id: 52, category: "taxation",
              step1: { question: "Co-owners share the tax burden based on their ownership percentage in which entity?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, each partner pays taxes on their share of profits based on the ownership percentage in the partnership agreement." },
              step2: { scenario: "Steve owns 60 percent and his partner owns 40 percent of their consulting business. Each pays taxes on their respective share of the profits.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Steve",
                       correctAnswer: "Partnership",
                       explanation: "Steve's partnership divides the tax burden by ownership. Steve pays taxes on 60 percent of profits and his partner on 40 percent." } },
            { id: 53, category: "taxation",
              step1: { question: "Which business type avoids corporate level taxation completely?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship avoids corporate taxes entirely. Only the owner pays taxes on business income through their personal return." },
              step2: { scenario: "Rachel wants to minimize her tax paperwork. She likes that her small craft business does not have to pay any business level taxes.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Rachel",
                       correctAnswer: "Proprietorship",
                       explanation: "Rachel's proprietorship avoids corporate taxes. She only files personal taxes with her business income included." } },
            { id: 54, category: "taxation",
              step1: { question: "Shareholders may pay taxes on dividends after the company paid taxes in which type?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, shareholders pay personal taxes on dividends even though the company already paid corporate tax on those profits." },
              step2: { scenario: "Kevin received dividends from his investment. The business already paid corporate tax on the profits, but Kevin still has to pay personal tax on his dividend income.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Kevin",
                       correctAnswer: "Corporation",
                       explanation: "Kevin's corporation has double taxation. The company paid tax first, then Kevin pays personal tax on his dividends." } },
            { id: 55, category: "taxation",
              step1: { question: "One tax return covers both business and personal income in which business type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the owner files one tax return that includes both personal and business income together." },
              step2: { scenario: "Nicole runs a dog walking business. She files just one tax return that includes her wages from her part time job and her dog walking income together.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Nicole",
                       correctAnswer: "Proprietorship",
                       explanation: "Nicole's proprietorship allows one tax return for everything. Her business income is part of her personal return." } },
            { id: 56, category: "taxation",
              step1: { question: "Profits flow through to multiple owners without business level tax in which entity?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, profits flow through to partners without any tax at the business level. Partners pay on their personal returns." },
              step2: { scenario: "James and his partner share profits from their marketing agency. The business itself does not pay income tax. Each partner pays taxes on their share.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbb", characterName: "James",
                       correctAnswer: "Partnership",
                       explanation: "James's partnership has pass-through taxation. No business level tax is paid. Each partner reports their share personally." } },
            { id: 57, category: "taxation",
              step1: { question: "Which business type has its profits taxed at the corporate rate?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation's profits are taxed at the corporate tax rate, which is separate from the personal tax rates of shareholders." },
              step2: { scenario: "Laura's company made a large profit this year. The business must pay the corporate tax rate on these earnings before any dividends go to shareholders.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Laura",
                       correctAnswer: "Corporation",
                       explanation: "Laura's corporation pays the corporate tax rate on profits. This is separate from any personal taxes shareholders pay." } },
            { id: 58, category: "taxation",
              step1: { question: "Business losses can offset personal income for tax purposes in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, business losses can often offset other personal income, potentially reducing the owner's overall tax burden." },
              step2: { scenario: "Chris had a loss in his photography business this year. His accountant said he might be able to use this loss to reduce taxes on his other income.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfa8", characterName: "Chris",
                       correctAnswer: "Proprietorship",
                       explanation: "Chris's proprietorship allows business losses to offset personal income. This can reduce his overall tax burden." } },
            { id: 59, category: "taxation",
              step1: { question: "Each co-owner files their share of profits on their own return in which entity?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, each co-owner files their own personal return that includes their share of the business profits." },
              step2: { scenario: "Tom and his cousin each own half of a plumbing business. At tax time, each files their own return showing half of the business profits.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udd27", characterName: "Tom",
                       correctAnswer: "Partnership",
                       explanation: "Tom's partnership requires each partner to file separately. Each reports their share of profits on their personal return." } },
            { id: 60, category: "taxation",
              step1: { question: "Which business type must file both corporate returns and shareholder personal returns?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation must file corporate tax returns, and shareholders must also file personal returns for any dividends received." },
              step2: { scenario: "Amy's business files its own corporate tax return every year. As a shareholder, Amy also files her personal return reporting any dividends she received.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Amy",
                       correctAnswer: "Corporation",
                       explanation: "Amy's corporation requires multiple filings. The company files corporate returns and each shareholder files personal returns." } },
            { id: 61, category: "formation",
              step1: { question: "Which business type requires articles of incorporation to form?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation must file articles of incorporation with the state government to legally form the business." },
              step2: { scenario: "Carlos wants to start a formal business. His lawyer told him he needs to file official documents called articles of incorporation with the state.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Carlos",
                       correctAnswer: "Corporation",
                       explanation: "Carlos is forming a corporation, which requires filing articles of incorporation with the government." } },
            { id: 62, category: "formation",
              step1: { question: "Which business type is the simplest and fastest to start?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship is the simplest to start. The owner can begin operating immediately with minimal paperwork." },
              step2: { scenario: "Jenny wants to start selling her handmade jewelry this weekend. She does not want to deal with any complicated legal documents or government filings.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Jenny",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship allows Jenny to start selling immediately. She can begin with almost no formal requirements." } },
            { id: 63, category: "formation",
              step1: { question: "Which business type requires the most legal paperwork to establish?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations require the most paperwork including articles of incorporation, bylaws, stock certificates, and government filings." },
              step2: { scenario: "Steve is starting a business. His accountant warned him that this type of company has many legal documents to prepare and file with the government.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Steve",
                       correctAnswer: "Corporation",
                       explanation: "Steve is forming a corporation, which has the most legal requirements including multiple documents and government filings." } },
            { id: 64, category: "formation",
              step1: { question: "A written agreement between co-owners is typical for which business type?",
                       correctAnswer: "Partnership",
                       explanation: "Partnerships typically have a written partnership agreement that describes how owners will share profits, make decisions, and handle disputes." },
              step2: { scenario: "Rachel and her friend want to start a business together. Their lawyer recommends they create a written agreement about how to share profits and responsibilities.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Rachel",
                       correctAnswer: "Partnership",
                       explanation: "Rachel is forming a partnership. A written partnership agreement helps co-owners understand their rights and duties." } },
            { id: 65, category: "formation",
              step1: { question: "Which business type can be started with no formal registration in many cases?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship often requires no formal registration to start. The owner simply begins doing business." },
              step2: { scenario: "Kevin wants to start mowing lawns in his neighborhood. He can just start advertising and working without filing any business papers with the government.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udf3e", characterName: "Kevin",
                       correctAnswer: "Proprietorship",
                       explanation: "Kevin can start a proprietorship without formal registration. He can begin his lawn mowing business immediately." } },
            { id: 66, category: "formation",
              step1: { question: "Which business type must file documents with the state government to exist?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation must file formation documents with the state government. It does not exist until the state approves the filing." },
              step2: { scenario: "Nicole received approval from the state government for her company. The state reviewed and approved her formation documents before she could legally operate.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Nicole",
                       correctAnswer: "Corporation",
                       explanation: "Nicole formed a corporation, which requires state government approval. The business legally exists after filing is approved." } },
            { id: 67, category: "formation",
              step1: { question: "The owner can start operating immediately without formalities in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, the owner can start operating immediately without formal paperwork or legal processes." },
              step2: { scenario: "James decided to start a tutoring business today. He immediately started advertising and taking students without any formal business setup process.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfeb", characterName: "James",
                       correctAnswer: "Proprietorship",
                       explanation: "James started a proprietorship, which requires no formal setup. He could begin tutoring immediately." } },
            { id: 68, category: "formation",
              step1: { question: "Multiple owners should create a written agreement in which business type?",
                       correctAnswer: "Partnership",
                       explanation: "When multiple owners form a partnership, they should create a written partnership agreement to define their relationship." },
              step2: { scenario: "Amy and two friends are starting a craft business together. Their advisor told them to write down how they will share work, profits, and make decisions.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udfa8", characterName: "Amy",
                       correctAnswer: "Partnership",
                       explanation: "Amy is forming a partnership. A written agreement helps all partners understand their roles and responsibilities." } },
            { id: 69, category: "formation",
              step1: { question: "Which business type requires a board of directors and corporate bylaws?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation must have a board of directors and adopt corporate bylaws that govern how the business operates." },
              step2: { scenario: "Chris is setting up his company. He needs to write bylaws and appoint people to serve on the board of directors before the company can operate.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Chris",
                       correctAnswer: "Corporation",
                       explanation: "Chris is forming a corporation, which requires both a board of directors and corporate bylaws." } },
            { id: 70, category: "formation",
              step1: { question: "Which business type has the lowest startup costs?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship has the lowest startup costs because it requires no legal fees, filing fees, or formal documents." },
              step2: { scenario: "Laura wants to start a business but has very little money. She wants to avoid spending money on lawyers and government filing fees.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Laura",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship has minimal startup costs. Laura can begin without paying for legal documents or filing fees." } },
            { id: 71, category: "formation",
              step1: { question: "State filing and registration are required before operating which type of business?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation must complete state filing and registration before it can legally operate as a business." },
              step2: { scenario: "David submitted his business's paperwork to the state last week. He must wait for the state to process and approve the registration before starting operations.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "David",
                       correctAnswer: "Corporation",
                       explanation: "David is forming a corporation, which requires state registration and approval before he can operate." } },
            { id: 72, category: "formation",
              step1: { question: "Which business type begins when the individual starts doing business?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship is formed the moment an individual begins conducting business activities." },
              step2: { scenario: "Emma made her first sale of homemade cookies to a neighbor. At that moment, she had started a business even without any formal papers.",
                       avatar: "\ud83d\udc69\u200d\ud83c\udf73", characterName: "Emma",
                       correctAnswer: "Proprietorship",
                       explanation: "Emma started a proprietorship simply by making her first sale. No formal process was needed." } },
            { id: 73, category: "formation",
              step1: { question: "An agreement defining profit sharing is recommended for which business type?",
                       correctAnswer: "Partnership",
                       explanation: "Partnerships should have an agreement that defines how profits and losses will be shared among partners." },
              step2: { scenario: "Tom and his sister are starting a photography business together. They need to agree in writing about how to split the money they earn.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfa8", characterName: "Tom",
                       correctAnswer: "Partnership",
                       explanation: "Tom is forming a partnership. A profit sharing agreement helps avoid disputes between partners later." } },
            { id: 74, category: "formation",
              step1: { question: "Which business type requires ongoing compliance with state corporate laws?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations must comply with ongoing state requirements including annual reports, meetings, and record keeping." },
              step2: { scenario: "Sara's business must file annual reports with the state and hold required meetings. Failing to do this could cause the company to lose its status.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Sara",
                       correctAnswer: "Corporation",
                       explanation: "Sara's corporation has ongoing compliance requirements. She must follow state corporate laws continuously." } },
            { id: 75, category: "formation",
              step1: { question: "Which business type requires no special documents to form?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship requires no special documents to form. The business exists when the owner starts operating." },
              step2: { scenario: "Mike wants to start fixing computers for people in his town. He checks and finds he does not need any special legal documents to begin.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbb", characterName: "Mike",
                       correctAnswer: "Proprietorship",
                       explanation: "Mike can start a proprietorship without any special formation documents. He simply begins offering services." } },
            { id: 76, category: "formation",
              step1: { question: "Two or more people joining together should formally agree on terms in which entity?",
                       correctAnswer: "Partnership",
                       explanation: "When two or more people form a partnership, they should formally agree on terms including roles, duties, and profit sharing." },
              step2: { scenario: "Anna and her two cousins want to open a salon together. Before starting, they sit down to write out how they will work together and share responsibilities.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Anna",
                       correctAnswer: "Partnership",
                       explanation: "Anna is forming a partnership with her cousins. They should agree on terms before starting the business." } },
            { id: 77, category: "formation",
              step1: { question: "Which business type has the most expensive and complex formation process?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations have the most expensive formation due to legal fees, filing fees, and required professional assistance." },
              step2: { scenario: "Lisa is shocked at how much it costs to form her business. Between lawyer fees and state filing costs, the process is expensive and complex.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Lisa",
                       correctAnswer: "Corporation",
                       explanation: "Lisa is forming a corporation, which has the highest formation costs due to legal and government requirements." } },
            { id: 78, category: "formation",
              step1: { question: "The business starts when the owner decides to offer services in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship starts when the owner decides to offer services or sell goods. No formal process is needed." },
              step2: { scenario: "Bob told his neighbors he would start walking their dogs for a fee. His dog walking business began the moment he made that decision.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Bob",
                       correctAnswer: "Proprietorship",
                       explanation: "Bob started a proprietorship simply by deciding to offer dog walking services. No paperwork was required." } },
            { id: 79, category: "formation",
              step1: { question: "Which business type may need help from a lawyer to form properly?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations often need legal help to prepare and file all required documents and to ensure compliance with laws." },
              step2: { scenario: "Maria hired a lawyer to help set up her business. The lawyer prepared many documents and filed them with the state government.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Maria",
                       correctAnswer: "Corporation",
                       explanation: "Maria needed a lawyer for her corporation. The complex requirements usually require professional legal help." } },
            { id: 80, category: "formation",
              step1: { question: "Co-owners can verbally agree but should have a written contract in which type?",
                       correctAnswer: "Partnership",
                       explanation: "Partners can form with a verbal agreement but should have a written contract to prevent misunderstandings and disputes." },
              step2: { scenario: "John and his friend agreed to start a business together with a handshake. Their advisor strongly recommended putting their agreement in writing.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "John",
                       correctAnswer: "Partnership",
                       explanation: "John is forming a partnership. While verbal agreements work, a written contract protects both partners." } },
            { id: 81, category: "lifetime",
              step1: { question: "Which business type continues to exist even if owners change?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation has perpetual existence. It continues operating regardless of changes in shareholders or ownership." },
              step2: { scenario: "Bob owns shares in a business. When he sells his shares to another person, the company continues operating without any interruption.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Bob",
                       correctAnswer: "Corporation",
                       explanation: "Bob's corporation has perpetual existence. The business continues even when shareholders sell their shares." } },
            { id: 82, category: "lifetime",
              step1: { question: "The business ends when the owner dies or retires in which type of entity?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship ends when the owner dies or decides to stop operating. The business does not have a separate existence." },
              step2: { scenario: "Maria runs a small tailoring shop by herself. When she retires next year, the business will close because it cannot exist without her.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Maria",
                       correctAnswer: "Proprietorship",
                       explanation: "Maria's proprietorship will end when she retires. The business depends on her existence as the sole owner." } },
            { id: 83, category: "lifetime",
              step1: { question: "Perpetual existence is a feature of which business type?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations have perpetual existence, meaning they can continue operating indefinitely regardless of owner changes." },
              step2: { scenario: "John wants to build a company that will last for generations. He wants it to continue operating long after he is no longer involved.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "John",
                       correctAnswer: "Corporation",
                       explanation: "A corporation has perpetual existence. John's company can continue for generations even after his involvement ends." } },
            { id: 84, category: "lifetime",
              step1: { question: "Which business type might dissolve when a co-owner leaves or dies?",
                       correctAnswer: "Partnership",
                       explanation: "A partnership may dissolve when a partner leaves, dies, or becomes unable to participate unless the agreement says otherwise." },
              step2: { scenario: "Lisa and her partner Tom run a business together. Lisa is worried about what will happen to the business if Tom decides to leave.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Lisa",
                       correctAnswer: "Partnership",
                       explanation: "Lisa's partnership might dissolve if Tom leaves. The business existence depends on both partners continuing." } },
            { id: 85, category: "lifetime",
              step1: { question: "Ownership can be transferred by selling shares in which business type?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, ownership is represented by shares that can be freely bought and sold without affecting the business." },
              step2: { scenario: "Sara wants to sell part of her ownership in the company. She can sell some of her shares to new investors without closing the business.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Sara",
                       correctAnswer: "Corporation",
                       explanation: "Sara's corporation allows easy ownership transfer. She can sell shares without disrupting business operations." } },
            { id: 86, category: "lifetime",
              step1: { question: "The business has limited life tied to the owner in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship has limited life because the business is inseparable from the owner. When the owner stops, the business stops." },
              step2: { scenario: "Mike runs a repair shop by himself. The business will only exist as long as Mike wants to keep running it or is able to do so.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udd27", characterName: "Mike",
                       correctAnswer: "Proprietorship",
                       explanation: "Mike's proprietorship has limited life. The business exists only as long as he continues to operate it." } },
            { id: 87, category: "lifetime",
              step1: { question: "Which business type can exist for hundreds of years?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations can exist for hundreds of years because they have perpetual existence independent of their owners." },
              step2: { scenario: "Anna visited a famous company that has been in business for over 150 years. Many generations of owners have come and gone.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Anna",
                       correctAnswer: "Corporation",
                       explanation: "This corporation has perpetual existence. It has survived through many generations of different shareholders." } },
            { id: 88, category: "lifetime",
              step1: { question: "All partners must agree on succession to continue the business in which type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, continuing after a partner leaves or dies typically requires agreement among remaining partners." },
              step2: { scenario: "David's partner is retiring. David and the other partners must decide together how to handle the retiring partner's share of the business.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "David",
                       correctAnswer: "Partnership",
                       explanation: "David's partnership requires partners to agree on what happens when someone leaves. This affects business continuity." } },
            { id: 89, category: "lifetime",
              step1: { question: "The business cannot be inherited as a going concern in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship cannot be directly inherited as an operating business. The business ends when the owner dies." },
              step2: { scenario: "Emma wants her children to take over her business someday. She is disappointed to learn that her business will legally end when she dies.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Emma",
                       correctAnswer: "Proprietorship",
                       explanation: "Emma's proprietorship will end when she dies. Her children would need to start a new business with the assets." } },
            { id: 90, category: "lifetime",
              step1: { question: "Which business type offers the most stability for long term planning?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations offer the most stability because they have perpetual existence and are not affected by ownership changes." },
              step2: { scenario: "Carlos wants to sign a 30 year contract with a supplier. He needs a business structure that will definitely still exist in 30 years.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Carlos",
                       correctAnswer: "Corporation",
                       explanation: "A corporation provides Carlos with long term stability. Its perpetual existence supports 30 year contract planning." } },
            { id: 91, category: "lifetime",
              step1: { question: "The death of one owner may end the business in which type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, the death of one partner may cause the business to end unless the partnership agreement provides otherwise." },
              step2: { scenario: "Jenny and her partner run an accounting firm. Jenny is concerned about what would happen to their clients if her partner passed away suddenly.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Jenny",
                       correctAnswer: "Partnership",
                       explanation: "Jenny's partnership could end if her partner dies. The business continuity depends on partnership agreement provisions." } },
            { id: 92, category: "lifetime",
              step1: { question: "Which business type is best for building a legacy that outlasts the founder?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations are best for building a legacy because they can continue indefinitely through perpetual existence." },
              step2: { scenario: "Steve wants to build a business that his grandchildren and great grandchildren can still benefit from long after he is gone.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Steve",
                       correctAnswer: "Corporation",
                       explanation: "A corporation allows Steve to build a lasting legacy. The business can continue for many generations." } },
            { id: 93, category: "lifetime",
              step1: { question: "Business continuity depends solely on one person in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "In a proprietorship, business continuity depends entirely on the single owner. If they stop, the business stops." },
              step2: { scenario: "Rachel runs a pet grooming business alone. If she gets sick or goes on vacation, there is no one to keep the business running.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Rachel",
                       correctAnswer: "Proprietorship",
                       explanation: "Rachel's proprietorship depends entirely on her. Business continuity is tied to her personal availability." } },
            { id: 94, category: "lifetime",
              step1: { question: "New owners can easily join by buying shares in which business type?",
                       correctAnswer: "Corporation",
                       explanation: "In a corporation, new owners can easily join by purchasing shares, allowing for smooth ownership transitions." },
              step2: { scenario: "Kevin wants to bring new investors into his business. New investors can simply buy shares without disrupting existing operations.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "Kevin",
                       correctAnswer: "Corporation",
                       explanation: "Kevin's corporation makes it easy for new owners to join. They simply purchase shares from existing shareholders." } },
            { id: 95, category: "lifetime",
              step1: { question: "Changes in ownership require agreement from all owners in which type?",
                       correctAnswer: "Partnership",
                       explanation: "In a partnership, adding or removing partners typically requires agreement from all existing partners." },
              step2: { scenario: "Nicole wants to bring a new partner into the business. She must get approval from her current partners before adding anyone new.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Nicole",
                       correctAnswer: "Partnership",
                       explanation: "Nicole's partnership requires partner consent for ownership changes. All partners must agree to add new members." } },
            { id: 96, category: "lifetime",
              step1: { question: "The owner's retirement ends the business in which type of entity?",
                       correctAnswer: "Proprietorship",
                       explanation: "When the owner of a proprietorship retires, the business ends because it cannot exist separately from the owner." },
              step2: { scenario: "James has run his consulting business for 30 years. When he decides to retire, the business will close down with him.",
                       avatar: "\ud83d\udc68\u200d\ud83d\udcbc", characterName: "James",
                       correctAnswer: "Proprietorship",
                       explanation: "James's proprietorship will end when he retires. The business cannot continue without him as the owner." } },
            { id: 97, category: "lifetime",
              step1: { question: "Which business type allows seamless succession planning through share transfer?",
                       correctAnswer: "Corporation",
                       explanation: "Corporations allow seamless succession because ownership passes through share transfer without disrupting operations." },
              step2: { scenario: "Amy wants her daughter to take over the business someday. She plans to gradually transfer shares to her daughter over time.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Amy",
                       correctAnswer: "Corporation",
                       explanation: "Amy's corporation allows smooth succession planning. She can transfer shares to her daughter without closing the business." } },
            { id: 98, category: "lifetime",
              step1: { question: "The business may need to be dissolved and reformed when an owner leaves which type?",
                       correctAnswer: "Partnership",
                       explanation: "When a partner leaves a partnership, the business may need to be dissolved and a new partnership formed with remaining partners." },
              step2: { scenario: "Chris and two partners run a design firm. When one partner decided to leave, they had to close the old partnership and start a new one.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfa8", characterName: "Chris",
                       correctAnswer: "Partnership",
                       explanation: "Chris's partnership may face dissolution when a partner leaves. They often must reform with the remaining partners." } },
            { id: 99, category: "lifetime",
              step1: { question: "Which business type exists independently of any individual owner?",
                       correctAnswer: "Corporation",
                       explanation: "A corporation exists as a separate legal entity independent of any individual shareholder or owner." },
              step2: { scenario: "Laura invests in a large business. Even though thousands of people own shares and many sell their shares daily, the company continues normally.",
                       avatar: "\ud83d\udc69\u200d\ud83d\udcbc", characterName: "Laura",
                       correctAnswer: "Corporation",
                       explanation: "Laura's corporation exists independently of individual owners. The business continues regardless of share trading." } },
            { id: 100, category: "lifetime",
              step1: { question: "The business life is limited to the working life of the owner in which type?",
                       correctAnswer: "Proprietorship",
                       explanation: "A proprietorship's life is limited to how long the owner works. The business ends when the owner stops working." },
              step2: { scenario: "Tom has run his photography studio for 25 years. When he can no longer work due to health reasons, the studio will have to close.",
                       avatar: "\ud83d\udc68\u200d\ud83c\udfa8", characterName: "Tom",
                       correctAnswer: "Proprietorship",
                       explanation: "Tom's proprietorship is limited to his working life. When he stops working, the business must close." } }
        ];

        /* ====================================================================
           LOAD-TIME POOL INTEGRITY. startGame() refuses to run if this fails.
           ==================================================================== */
        const POOL_AUDIT = (function assertPoolIntegrity() {
            const errors = [];
            const ids = new Set();
            const byCat = {};
            MASTER_PROBLEM_POOL.forEach(function (p) {
                if (ids.has(p.id)) errors.push('duplicate pool id ' + p.id);
                ids.add(p.id);
                if (ENTITIES.indexOf(p.step1.correctAnswer) === -1) errors.push('id ' + p.id + ': step1 answer is not an entity');
                if (ENTITIES.indexOf(p.step2.correctAnswer) === -1) errors.push('id ' + p.id + ': step2 answer is not an entity');
                if (!byCat[p.category]) byCat[p.category] = [];
                byCat[p.category].push(p);
            });
            if (MASTER_PROBLEM_POOL.length !== 100) errors.push('pool size is ' + MASTER_PROBLEM_POOL.length + ', expected 100');

            /* Every named wave must be able to draw one item of EACH entity from its
               own category, or the stratified draw silently degrades. */
            WAVES.forEach(function (w) {
                const items = byCat[w.key] || [];
                if (items.length === 0) { errors.push('wave "' + w.key + '" has no pool category'); return; }
                /* Worst case the global deal sends a whole wave to ONE entity, so
                   every category must serve TAPS_PER_NAMED_WAVE of every entity.
                   This is what lets buildSession() drop its old rejection fallback:
                   a wave's category can ALWAYS serve whatever the bag deals it. */
                ENTITIES.forEach(function (e) {
                    const n = items.filter(function (p) { return p.step2.correctAnswer === e; }).length;
                    if (n < TAPS_PER_NAMED_WAVE) {
                        errors.push('wave "' + w.key + '" cannot draw ' + TAPS_PER_NAMED_WAVE + ' ' + e + ' scenarios (has ' + n + ')');
                    }
                });
                ENTITIES.forEach(function (e) {
                    if (!w.rows[e]) errors.push('wave "' + w.key + '" concept card has no row for ' + e);
                });
            });

            /* Finale supply. Worst case the named waves consume NAMED_MAX_PER_ENTITY
               items of one entity and the finale then asks for FINALE_TAPS - 1 more
               of the same one (it can never ask for all FINALE_TAPS - the draw
               forbids a one-note finale). If the pool cannot serve that, a round is
               silently dropped and the GRADED DENOMINATOR drifts below TOTAL_GRADED. */
            ENTITIES.forEach(function (e) {
                const n = MASTER_PROBLEM_POOL.filter(function (p) { return p.step1.correctAnswer === e; }).length;
                const worst = NAMED_MAX_PER_ENTITY + (FINALE_TAPS - 1);
                if (n < worst) {
                    errors.push('pool cannot serve a worst-case draw of ' + worst + ' ' + e + ' (has ' + n + ')');
                }
            });

            /* The name recast must cover EVERY authored name, or an uncovered
               one stays a live class-5 channel, and its gender roster must be
               long enough that two names in one item cannot collide. */
            const seenNames = new Set();
            MASTER_PROBLEM_POOL.forEach(function (p) {
                const n = p.step2.characterName;
                seenNames.add(n);
                if (!CAST[n]) errors.push('id ' + p.id + ': character name "' + n + '" is not in CAST, so it is never recast');
                if (!/^[A-Za-z]+$/.test(n)) errors.push('id ' + p.id + ': character name "' + n + '" is not plain ASCII (CAST_RE would misfire)');
            });
            if (NAME_ROSTER_M.length !== CAST_M.length) errors.push('male roster is shorter than the male cast');
            if (NAME_ROSTER_F.length !== CAST_F.length) errors.push('female roster is shorter than the female cast');
            NAME_ROSTER_M.concat(NAME_ROSTER_F).forEach(function (n) {
                if (CAST[n]) errors.push('roster name "' + n + '" is also an authored cast name');
                if (n === DEMO_NAME) errors.push('roster name "' + n + '" collides with the warm-up character');
            });

            /* Demo disjointness: no teach beat may reuse a graded item's words. */
            MASTER_PROBLEM_POOL.forEach(function (p) {
                if (p.step2.scenario.indexOf(DEMO_SCENARIO) !== -1 || DEMO_SCENARIO.indexOf(p.step2.scenario) !== -1) {
                    errors.push('id ' + p.id + ': graded scenario collides with the learning-page warm-up');
                }
                if (p.step2.characterName === DEMO_NAME) {
                    errors.push('id ' + p.id + ': graded item reuses the warm-up character name');
                }
            });

            /* No graded round may be answerable from the wave card alone: the card
               states the RULE for each entity, the items describe a business. */
            if (TOTAL_GRADED !== WAVES.length * TAPS_PER_NAMED_WAVE + FINALE_TAPS) {
                errors.push('TOTAL_GRADED does not match the wave plan');
            }

            const report = { ok: errors.length === 0, errors: errors, poolSize: MASTER_PROBLEM_POOL.length };
            if (!report.ok) console.error('[Ch1 G1] POOL INTEGRITY FAILED', errors);
            try { window.__POOL_AUDIT = report; } catch (e) { /* no window (harness) */ }
            return report;
        })();

        function shuffleArray(arr) {
            const a = arr.slice();
            for (let i = a.length - 1; i > 0; i--) {
                const j = Math.floor(Math.random() * (i + 1));
                const t = a[i]; a[i] = a[j]; a[j] = t;
            }
            return a;
        }

        /* ====================================================================
           sec.25 STRATIFIED DRAW - balance is a property of the DRAW, not the pool.

           Named waves : the 10 named taps are stratified GLOBALLY as 4 / 3 / 3
                         (NAMED_BASE / NAMED_EXTRA, derived) and dealt two to a
                         wave. WHICH entity gets the fourth is re-rolled every
                         session. There is NO per-wave entity rule at all - a
                         wave may legally ask the same entity twice.
           Finale      : 3 concept-form items, each drawn freely, redrawn only
                         if all three landed on the same entity.
           An item drawn in either form is never drawn again in a session, so the
           step1/step2 answer identity (true for all 100 items) can never leak.

           WHY THERE IS NO "one of each" RULE ANYWHERE ANY MORE.
           A correct answer is revealed after every decision (ruling A19 - the
           reveal stays, it is the feedback), so every "exactly one of each"
           quota hands the last tap of that group to a student who reads nothing.
           The 2026-07-27 build guaranteed 1 P + 1 PT + 1 C per named wave and an
           exact 2/2/1 finale: that reader passed 94.6% with the avatar tell
           (06b's exact enumeration: 97.96%).

           A138 MEASURED, 20,000 sessions per design, exact-Bayesian blind reader
           (scratchpad cf13.py; the reader knows the design and does exact
           posterior elimination, so it is STRONGER than the in-page tripwire and
           its numbers are not comparable with the tripwire's):
             finale "exactly one of each"            26.51% pass, 100% ceiling
             finale free, never three of a kind      13.12% pass,  92% ceiling  <- shipped
             + "a wave's two taps must differ"       22.32% pass
             (control: the 20-round build it replaces  15.70% on the same reader)
           So the 13-round draw is HARDER to beat blind than the 20-round one it
           replaces, and the two constraints that look tidiest are the two that
           give the game away.

           Fixed-choice ceiling: 4 named + at most 2 finale = 6 of 13 = 46%,
           against a 60% pass mark (8 of 13 = 61.5% needed). Measured 0.0000%.
           sec.25-quater rule 5 - what the fix created: nothing new. Positional
           reading is unchanged (the three buttons are a fixed, never-shuffled
           order, so it IS the fixed-choice reader), and the round-number reader
           stays flat because the 4/3/3 assignment is re-rolled per session.
           ==================================================================== */
        function buildSession() {
            const used = new Set();
            const rounds = [];

            function pick(candidates) {
                const free = candidates.filter(function (p) { return !used.has(p.id); });
                if (free.length === 0) return null;
                const chosen = free[Math.floor(Math.random() * free.length)];
                used.add(chosen.id);
                return chosen;
            }

            /* (The old supply() helper is gone with the rejection loop it served -
               POOL_AUDIT now proves the same property once, at load, for every
               category. A129: no dead helpers left behind.) */

            /* Build the 4/3/3 bag: every entity gets NAMED_BASE taps and
               NAMED_EXTRA entities, chosen fresh every session, get one more.
               Then deal it two to a wave, in order, with NO per-wave rule.
               There is no rejection loop and no fallback shape: POOL_AUDIT
               asserts every category serves TAPS_PER_NAMED_WAVE of every
               entity, so ANY deal is servable, and the five waves draw from
               five DIFFERENT categories so they never compete for an item.
               The named block is therefore always exactly NAMED_TAPS rounds and
               the graded denominator cannot drift. */
            const extras = shuffleArray(ENTITIES).slice(0, NAMED_EXTRA);
            let namedBag = [];
            ENTITIES.forEach(function (e) {
                const n = NAMED_BASE + (extras.indexOf(e) === -1 ? 0 : 1);
                for (let i = 0; i < n; i++) namedBag.push(e);
            });
            namedBag = shuffleArray(namedBag);

            WAVES.forEach(function (w, wi) {
                const waveRounds = [];
                namedBag.slice(wi * TAPS_PER_NAMED_WAVE, (wi + 1) * TAPS_PER_NAMED_WAVE).forEach(function (e) {
                    const item = pick(MASTER_PROBLEM_POOL.filter(function (p) {
                        return p.category === w.key && p.step2.correctAnswer === e;
                    }));
                    if (!item) return;
                    waveRounds.push({ waveIndex: wi, form: 'scenario', item: item, answer: e });
                });
                shuffleArray(waveRounds).forEach(function (r) { rounds.push(r); });
            });

            /* Finale: FINALE_TAPS free draws, redrawn only if they all landed on
               ONE entity. Guaranteeing one of each would make the last finale tap
               certain to a student who reads nothing - measured 26.51% blind pass
               against 13.12% for this shape. */
            let finaleBag = [];
            for (let guard = 0; guard < 200; guard++) {
                finaleBag = [];
                for (let n = 0; n < FINALE_TAPS; n++) {
                    finaleBag.push(ENTITIES[Math.floor(Math.random() * ENTITIES.length)]);
                }
                let distinct = 0;
                ENTITIES.forEach(function (e) { if (finaleBag.indexOf(e) !== -1) distinct++; });
                if (distinct > 1) break;
            }
            const finale = [];
            finaleBag.forEach(function (e) {
                const item = pick(MASTER_PROBLEM_POOL.filter(function (p) {
                    return p.step1.correctAnswer === e;
                }));
                if (!item) return;
                finale.push({ waveIndex: WAVES.length, form: 'concept', item: item, answer: e });
            });
            shuffleArray(finale).forEach(function (r) { rounds.push(r); });

            return { rounds: rounds };
        }

        /* ====================================================================
           Load-time sec.25 tripwire. TWO readers, not one.

           sec.25-quater rule 1: enumerating only the fixed-choice reader is what
           let this game ship at a 97.96% blind pass. The audit below also plays
           the ELIMINATION reader - the class-8/10 strategy that beat the shipped
           build - which knows the draw's constraints (the 10 named taps are
           4/3/3 with the 4 going to an entity it does not know in advance; the
           finale is never one-note) and uses the answers revealed earlier IN THE
           SAME SESSION.

           ⚠ A138: every assertion below is DERIVED from TAPS_PER_NAMED_WAVE /
           FINALE_TAPS. The two 20-round assertions that this file used to carry
           are gone rather than rescaled, because at 2 taps per wave they had
           become UNFALSIFIABLE: "a wave never holds 3 of one entity" cannot fail
           when a wave holds 2 rounds, and "the finale carries one of each" is
           now deliberately FALSE. They are replaced by the invariants that CAN
           break here - the wave's round count, and the one-note finale.

           sec.25-quater rule 4: a live tripwire is not a complete one. This
           proves the two readers it names have not got worse; it says nothing
           about a reader nobody has thought of. The independent measurement is
           the 06b re-derivation, not this.

           ⚠ Under ruling A19 sec.25 is a DESIGN SIGNAL, not a ship blocker, so
           the elimination bar reports loudly but does NOT refuse to start - a
           formative game must never be bricked by a sampling wobble. Only the
           original fixed-choice ceiling keeps its refuse-to-start behaviour.
           ==================================================================== */
        const DRAW_AUDIT = (function auditDrawBalance() {
            const SAMPLES = 200;
            const ELIMINATION_BAR_PCT = 15;   /* A138: THIS reader measured 7.45% over 20,000 real 13-round
                                                 sessions (was 5.6% at 20 rounds). 200 samples wobble by
                                                 ~1.9pp (1 SD), so 15 is ~4 SD of headroom, as before. */
            let worst = 0, wrongSize = 0, waveSizeBad = 0, namedSkew = 0, finaleOneNote = 0;
            let elimPasses = 0, elimBest = 0;
            const passNeeded = Math.ceil((PASS_MARK / 100) * TOTAL_GRADED);

            for (let s = 0; s < SAMPLES; s++) {
                const sess = buildSession();
                if (sess.rounds.length !== TOTAL_GRADED) wrongSize++;
                const counts = { "Proprietorship": 0, "Partnership": 0, "Corporation": 0 };
                sess.rounds.forEach(function (r) { counts[r.answer]++; });
                ENTITIES.forEach(function (e) { if (counts[e] > worst) worst = counts[e]; });

                /* shape checks the A138 draw must satisfy.
                   1. the named block is 4/3/3: exactly NAMED_EXTRA entities carry
                      NAMED_BASE + 1 and the rest carry exactly NAMED_BASE;
                   2. every named wave holds exactly TAPS_PER_NAMED_WAVE rounds
                      (this is what catches a silently dropped pick());
                   3. the finale is never all one entity. */
                const named = sess.rounds.filter(function (r) { return r.form === 'scenario'; });
                const fin = sess.rounds.filter(function (r) { return r.form === 'concept'; });
                let atExtra = 0, atBase = 0;
                ENTITIES.forEach(function (e) {
                    const n = named.filter(function (r) { return r.answer === e; }).length;
                    if (n === NAMED_BASE + 1) atExtra++;
                    else if (n === NAMED_BASE) atBase++;
                });
                if (atExtra !== NAMED_EXTRA || atBase !== ENTITIES.length - NAMED_EXTRA) namedSkew++;
                for (let w = 0; w < WAVES.length; w++) {
                    if (named.filter(function (r) { return r.waveIndex === w; }).length !== TAPS_PER_NAMED_WAVE) waveSizeBad++;
                }
                if (fin.length > 1) {
                    let distinct = 0;
                    ENTITIES.forEach(function (e) {
                        if (fin.filter(function (r) { return r.answer === e; }).length > 0) distinct++;
                    });
                    if (distinct < 2) finaleOneNote++;
                }

                /* THE ELIMINATION READER. Reads no word of any item; tracks only
                   the answers already revealed, against the constraints above. */
                const seenNamed = { "Proprietorship": 0, "Partnership": 0, "Corporation": 0 };
                const seenFin = { "Proprietorship": 0, "Partnership": 0, "Corporation": 0 };
                let hits = 0;
                sess.rounds.forEach(function (r) {
                    let cand;
                    if (r.form === 'scenario') {
                        /* it knows the shape is 4/3/3 but not WHICH entity holds the 4:
                           an entity is out once it reaches the max, and out at
                           NAMED_BASE too once the extra slot has been spent elsewhere. */
                        const extraSpent = ENTITIES.filter(function (e) { return seenNamed[e] > NAMED_BASE; }).length;
                        cand = ENTITIES.filter(function (e) {
                            if (seenNamed[e] >= NAMED_MAX_PER_ENTITY) return false;
                            if (seenNamed[e] >= NAMED_BASE && extraSpent >= NAMED_EXTRA) return false;
                            return true;
                        });
                        if (cand.length === 0) cand = ENTITIES.filter(function (e) { return seenNamed[e] < NAMED_MAX_PER_ENTITY; });
                    } else {
                        /* the only finale constraint is "not all one entity", so it
                           bites on the LAST tap and only if every earlier one matched. */
                        const placed = seenFin["Proprietorship"] + seenFin["Partnership"] + seenFin["Corporation"];
                        const hit = ENTITIES.filter(function (e) { return seenFin[e] === placed && placed > 0; });
                        cand = (placed === FINALE_TAPS - 1 && hit.length === 1)
                            ? ENTITIES.filter(function (e) { return e !== hit[0]; })
                            : ENTITIES.slice();
                    }
                    if (cand.length === 0) cand = ENTITIES.slice();
                    if (cand[Math.floor(Math.random() * cand.length)] === r.answer) hits++;
                    if (r.form === 'scenario') { seenNamed[r.answer]++; }
                    else { seenFin[r.answer]++; }
                });
                if (hits > elimBest) elimBest = hits;
                if (hits >= passNeeded) elimPasses++;
            }

            const ceilingPct = Math.round((worst / TOTAL_GRADED) * 100);
            const elimPassPct = Math.round((elimPasses / SAMPLES) * 1000) / 10;
            const errors = [];
            const warnings = [];
            if (wrongSize > 0) errors.push(wrongSize + ' of ' + SAMPLES + ' sessions did not draw ' + TOTAL_GRADED + ' rounds');
            if (namedSkew > 0) errors.push('the ' + NAMED_TAPS + ' named taps were not ' + NAMED_MAX_PER_ENTITY + '/' + NAMED_BASE + '/' + NAMED_BASE + ' in ' + namedSkew + ' of ' + SAMPLES + ' sessions');
            if (waveSizeBad > 0) errors.push('a named wave did not hold ' + TAPS_PER_NAMED_WAVE + ' rounds in ' + waveSizeBad + ' checks');
            if (finaleOneNote > 0) errors.push('the finale was all one entity in ' + finaleOneNote + ' of ' + SAMPLES + ' sessions');
            if (ceilingPct >= PASS_MARK) errors.push('single-entity ceiling ' + ceilingPct + '% reaches the ' + PASS_MARK + '% pass mark');
            if (elimPassPct > ELIMINATION_BAR_PCT) {
                warnings.push('elimination reader passes ' + elimPassPct + '% of sessions, above the recorded ' + ELIMINATION_BAR_PCT + '% bar');
            }
            const report = {
                ok: errors.length === 0, errors: errors, warnings: warnings, samples: SAMPLES,
                worstEntityCount: worst, ceilingPct: ceilingPct, passMark: PASS_MARK,
                eliminationPassPct: elimPassPct, eliminationBestOf: elimBest,
                eliminationBarPct: ELIMINATION_BAR_PCT
            };
            if (!report.ok) console.error('[Ch1 G1] DRAW AUDIT FAILED', errors);
            if (warnings.length) console.error('[Ch1 G1] sec.25 TRIPWIRE', warnings);
            try { window.__DRAW_AUDIT = report; } catch (e) { /* no window (harness) */ }
            return report;
        })();

        /* ====================================================================
           sec.18.4 SCORM 1.2 wrapper
           ==================================================================== */
        const SCORM = {
            API: null, startTime: null, finished: false, initialized: false, bestScore: -1,
            /* A307 - set true ONLY where an LMSSetValue for cmi.core.score.raw was
               actually issued. The confirmation screen says "your score has been
               sent" off this flag, so the sentence is a MEASUREMENT rather than an
               assumption: a zero-correct abandon writes nothing at all under A190,
               and telling that student their work is saved would be a lie printed on
               the screen. It is read, never written, outside this object. */
            wroteScore: false,
            init() {
                try {
                    this.API = this.findAPI(window);
                    if (!this.API && window.opener) this.API = this.findAPI(window.opener);
                    if (!this.API) return;
                    let initResult;
                    try { initResult = this.API.LMSInitialize(''); }
                    catch (e) { console.warn('SCORM LMSInitialize threw:', e); return; }
                    if (initResult !== 'true' && initResult !== true) { console.warn('SCORM LMSInitialize returned:', initResult); return; }
                    this.initialized = true;
                    // §18.4 best-score SEED (2026-07-27, register O8). Without this the guard in
                    // setScore() only protects within ONE page session: bestScore starts at -1 on
                    // every load, so an abandoned replay beats it and overwrites a stronger stored
                    // result — a learner at 95/passed written back to failed. Seeded from the LMS's
                    // own value; -1 (not 0) so a genuine 0 remains beatable.
                    try {
                      const priorRaw = parseFloat(this.API.LMSGetValue('cmi.core.score.raw'));
                      if (Number.isFinite(priorRaw)) this.bestScore = Math.max(this.bestScore, priorRaw);
                    } catch(e) { /* LMS may not expose a prior score */ }
                    this.startTime = new Date();
                    const status = this.API.LMSGetValue('cmi.core.lesson_status');
                    if (status === 'not attempted' || status === '') {
                        this.API.LMSSetValue('cmi.core.lesson_status', 'incomplete');
                        this._commit();
                    }
                } catch (e) { console.warn('SCORM init failed:', e); }
            },
            findAPI(win) {
                try {
                    let attempts = 0;
                    while (win && attempts < 10) {
                        try { if (win.API) return win.API; } catch (e) { /* cross-origin ancestor - keep walking */ }
                        let p = null;
                        try { p = win.parent; } catch (e) { break; }
                        if (p && p !== win) { attempts++; win = p; } else break;
                    }
                } catch (e) { /* SCORM unavailable - the game must not die */ }
                return null;
            },
            _commit() {
                if (!this.initialized) return false;
                try {
                    const r = this.API.LMSCommit('');
                    if (r !== 'true' && r !== true) { console.warn('SCORM LMSCommit returned:', r); return false; }
                    return true;
                } catch (e) { console.warn('SCORM _commit error:', e); return false; }
            },
            /* Receives a PERCENTAGE 0-100 derived from firstTryCorrect / rounds. Never a point total.

               A205 / A184 (David, 2026-08-05). `partial` marks an ABANDONED attempt.
               Its honest score is still recorded, against the FULL denominator, but it
               may never write 'passed' - 'incomplete' is what tells the LMS the attempt
               was not finished, which is why the low number can afford to be honest.

               ★ A199 / CH1-G38 SHAPE: THE STATUS WRITE IS DECOUPLED FROM THE BEST-SCORE
               GUARD. The old shape kept the status write INSIDE `if (score > bestScore)`.
               That was harmless only while nothing ever wrote a partial; the moment
               A205 lets an abandoned run bank 62/incomplete, a LATER COMPLETED run that
               earns exactly 62 no longer beats the stored best, writes nothing at all,
               and the gradebook keeps 'incomplete' while the screen says PASSED. That
               defect is invisible on a phone and shows up only in a real LMS. THE
               DECOUPLING IS THE REMEDY AND IT STAYS: the status block below sits
               OUTSIDE the score guard and therefore runs on EVERY call, whether or not
               this run beat the stored best.

               ⛔ A273 (David, 2026-08-09) - THE PASS TEST READS `s`, NOT `this.bestScore`.
               It used to read `this.bestScore`, which init() SEEDS FROM THE LMS (l.2079),
               so it included a number banked by an ABANDONED run. FIRED against
               `scripts/scorm_reject_shim.py` on the pre-fix build: a student abandons at
               80% (A184 correctly banks 80/'incomplete'), returns, and COMPLETES a run at
               8%. The results screen reads "NOT YET PASSED" and the gradebook recorded
               'passed'. That is the false pass A184 forbids, arriving one attempt later
               through the back door - an abandoned run minting a pass for a later failing
               one. Reading `s` was never what A199 required: A199's defect was the status
               write sitting INSIDE `if (score > bestScore)`, and DECOUPLING alone fixes
               it. Proven - A199's own case (a completed run earning exactly the stored
               best of 62) still writes 'passed' after this change, because the block runs
               outside the guard. This now matches CH1-G5, G25 and G37, which all gate on
               this run's own score.

               ★ AND IT NEVER DOWNGRADES A PASS ALREADY EARNED: the else-branch reads the
               STORED status back from the LMS, so a completed 8% run after a genuine
               90/'passed' leaves the pass alone (fired). The SCORE is protected
               separately by the `s > this.bestScore` guard, which is unchanged: an
               abandon that outscores an earlier completed pass still raises the number. */
            setScore(score, partial) {
                if (!this.initialized || this.finished) return;
                try {
                    const s = Math.max(0, Math.min(100, Math.round(score)));
                    if (s > this.bestScore) {
                        this.bestScore = s;
                        this.API.LMSSetValue('cmi.core.score.raw', String(s));
                        this.API.LMSSetValue('cmi.core.score.min', '0');
                        this.API.LMSSetValue('cmi.core.score.max', '100');
                        this.wroteScore = true;   /* A307 message flag only - reads nothing, grades nothing */
                    }
                    if (!partial && s >= PASS_MARK) {   /* A273: THIS run's score, never the LMS-seeded best */
                        this.API.LMSSetValue('cmi.core.lesson_status', 'passed');
                    } else if (this.API.LMSGetValue('cmi.core.lesson_status') !== 'passed') {
                        /* never downgrade a pass already banked by an earlier attempt */
                        this.API.LMSSetValue('cmi.core.lesson_status', 'incomplete');
                    }
                    this._commit();
                } catch (e) { console.warn('SCORM setScore error:', e); }
            },
            // A228 / A218 (David, 2026-08-06) -- THE MID-GAME EXIT WRITE.
            // A SEPARATE method, not a call to setScore(), and the reason is MEASURED rather
            // than argued: 45 of the 47 SCORM wrappers in this repo derive lesson_status
            // INSIDE setScore, so firing it from a page-closing path recorded `passed` for a
            // run the student ABANDONED. A218 makes this shape the fleet canonical abandon
            // write and forbids setScore() there; A228 ruled it the remedy for the free-tier
            // exit-path defect and RETIRED A223's literal `setScore(pct)` line.
            // A184: an honest partial against the FULL denominator with lesson_status left
            // `incomplete` -- the status is what carries the "they stopped early" fact, so the
            // number can afford to be plainly honest. This method can never write `passed`.
            // A210: a `passed` already banked is a FLOOR, never written down from, and it is
            // READ FROM THE LMS because the pass may have been earned in an attempt this page
            // knows nothing about.
            // The best-score guard is deliberately kept: an abandoned replay must not overwrite
            // a stronger stored result.
            // The entry guard and the commit call below are INHERITED VERBATIM from this file's
            // own setScore above. Six wrapper generations are in circulation here and they
            // agree on neither; hard-coding either one made this method DEAD CODE in the
            // legacy wrappers when it was tried on the donors.
            setPartialScore(score) {
                if (!this.initialized || this.finished) return;
                const s = Math.max(0, Math.min(100, Math.round(score)));
                if (!(s > this.bestScore)) return;
                this.bestScore = s;
                try {
                    this.API.LMSSetValue('cmi.core.score.raw', String(s));
                    this.API.LMSSetValue('cmi.core.score.min', '0');
                    this.API.LMSSetValue('cmi.core.score.max', '100');
                    this.wroteScore = true;   /* A307 message flag only - reads nothing, grades nothing */
                    if (this.API.LMSGetValue('cmi.core.lesson_status') !== 'passed') {
                        this.API.LMSSetValue('cmi.core.lesson_status', 'incomplete');
                    }
                    this._commit();
                } catch (e) { console.warn('SCORM setPartialScore error:', e); }
            },

            setSessionTime() {
                if (this.API && this.startTime) {
                    const elapsed = Math.floor((new Date() - this.startTime) / 1000);
                    const h = String(Math.floor(elapsed / 3600)).padStart(4, '0');
                    const m = String(Math.floor((elapsed % 3600) / 60)).padStart(2, '0');
                    const s = String(elapsed % 60).padStart(2, '0');
                    this.API.LMSSetValue('cmi.core.session_time', h + ':' + m + ':' + s);
                }
            },
            finish() {
                if (!this.initialized || this.finished) return;
                this.finished = true;
                this.setSessionTime();
                try {
                    this.API.LMSSetValue('cmi.core.exit', '');
                    this._commit();
                    const r = this.API.LMSFinish('');
                    if (r !== 'true' && r !== true) console.warn('SCORM LMSFinish returned:', r);
                } catch (e) { console.warn('SCORM finish error:', e); }
            }
        };
        SCORM.init();

        /* ====================================================================
           AUDIO
           ==================================================================== */
        const SoundController = {
            ctx: null, isMuted: false, unlocked: false,
            _ensureContext() {
                if (this.ctx) return true;
                try { this.ctx = new (window.AudioContext || window.webkitAudioContext)(); return true; }
                catch (e) { console.warn('Web Audio API not available'); return false; }
            },
            async unlock() {
                if (this.unlocked) return;
                if (!this._ensureContext()) return;
                if (this.ctx.state === 'suspended') {
                    try { await this.ctx.resume(); } catch (e) { console.warn('Audio unlock failed', e); return; }
                }
                this.unlocked = true;
            },
            play(type) {
                if (this.isMuted) return;
                if (!this._ensureContext()) return;
                if (this.ctx.state === 'suspended') { try { this.ctx.resume(); } catch (e) { /* ignore */ } return; }
                const o = this.ctx.createOscillator();
                const g = this.ctx.createGain();
                o.connect(g); g.connect(this.ctx.destination);
                const t = this.ctx.currentTime;
                switch (type) {
                    case 'success':
                        o.frequency.setValueAtTime(523.25, t);
                        o.frequency.setValueAtTime(659.25, t + 0.1);
                        o.frequency.setValueAtTime(783.99, t + 0.2);
                        g.gain.setValueAtTime(0.1, t);
                        g.gain.exponentialRampToValueAtTime(0.01, t + 0.35);
                        o.start(t); o.stop(t + 0.35);
                        break;
                    case 'error':
                        o.type = 'square';
                        o.frequency.setValueAtTime(200, t);
                        o.frequency.setValueAtTime(150, t + 0.1);
                        g.gain.setValueAtTime(0.1, t);
                        g.gain.exponentialRampToValueAtTime(0.01, t + 0.25);
                        o.start(t); o.stop(t + 0.25);
                        break;
                    case 'grow':
                        o.frequency.setValueAtTime(392.0, t);
                        o.frequency.setValueAtTime(587.33, t + 0.09);
                        g.gain.setValueAtTime(0.07, t);
                        g.gain.exponentialRampToValueAtTime(0.01, t + 0.22);
                        o.start(t); o.stop(t + 0.22);
                        break;
                    case 'tap':
                    default:
                        o.frequency.setValueAtTime(600, t);
                        g.gain.setValueAtTime(0.05, t);
                        g.gain.exponentialRampToValueAtTime(0.01, t + 0.06);
                        o.start(t); o.stop(t + 0.06);
                        break;
                }
            },
            toggle() {
                this.isMuted = !this.isMuted;
                const btn = document.getElementById('mute-btn');
                btn.textContent = this.isMuted ? '\uD83D\uDD07' : '\uD83D\uDD0A';
                btn.classList.toggle('muted', this.isMuted);
            }
        };
        function toggleMute() { SoundController.toggle(); }
        function playFeedback(type) { SoundController.play(type); }
        ['pointerdown', 'touchstart', 'mousedown', 'keydown'].forEach(function (evt) {
            window.addEventListener(evt, function () { SoundController.unlock(); }, { once: true, passive: true });
        });

        /* ====================================================================
           GAME STATE
           ==================================================================== */
        let session = { rounds: [] };
        let currentRound = 0;
        let firstTryCorrect = 0;      /* GRADED numerator - the ONLY one */
        let displayPoints = 0;        /* DISPLAY ONLY */
        let currentStreak = 0;        /* DISPLAY ONLY */
        let storefronts = { "Proprietorship": 0, "Partnership": 0, "Corporation": 0 };  /* DISPLAY ONLY */
        let waveCardShown = [];
        let showFeedbackOnWrong = false;   /* sec.12: DEFAULT OFF */
        let answerLocked = false;          /* sec.23 answer-surface lock */
        let hasExited = false;             /* A307 - set once the exit confirmation is shown */

        /* sec.23 / sec.23-bis TWO TOKENS, never one.
           currentRoundToken  - ANSWER identity, minted by the renderer.
           advanceTokenLive   - ADVANCE permit, minted ONLY where the beat RESOLVES.
           Deliberately NOT `advancedFromRound === currentRound`, which goes inert
           the instant currentRound++ runs. */
        let roundTokenSeq = 0;
        let currentRoundToken = 0;
        let advanceTokenLive = null;

        /* Renderer mint. sec.23-bis: painting a round does NOT make it advanceable,
           so this CLEARS the advance permit rather than minting one. */
        function mintRoundToken() {
            roundTokenSeq += 1;
            currentRoundToken = roundTokenSeq;
            advanceTokenLive = null;
            return currentRoundToken;
        }
        /* Resolution mint. sec.23-bis: the ONLY place an advance permit is created. */
        function mintAdvanceToken() {
            roundTokenSeq += 1;
            advanceTokenLive = roundTokenSeq;
            return advanceTokenLive;
        }
        function consumeAdvanceToken(token) {
            if (advanceTokenLive === null) return false;
            if (!Number.isInteger(token)) return false;
            if (token !== advanceTokenLive) return false;
            advanceTokenLive = null;   /* one-shot: every later tap with this token is inert */
            return true;
        }

        function escapeHtml(value) {
            return String(value === null || value === undefined ? '' : value)
                .replace(/&/g, '&amp;').replace(/</g, '&lt;')
                .replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&#39;');
        }

        /* ====================================================================
           SCREENS
           ==================================================================== */
        function showScreen(id) {
            /* A307 latch - once the exit confirmation is up, nothing may replace it.
               See showExitConfirmation() for the timer that would otherwise steal it
               back. This is the SOLE screen switcher in this file, so one line here
               closes every route in; putting it on the call sites would not. */
            if (hasExited && id !== 'exit-screen') return;
            document.querySelectorAll('.screen').forEach(function (s) { s.classList.remove('active'); });
            document.getElementById(id).classList.add('active');
            window.scrollTo(0, 0);
            const inGame = (id === 'game-screen');
            document.body.classList.toggle('in-game', inGame);
            if (inGame) requestAnimationFrame(seatMuteBtn);
        }
        function seatMuteBtn() {
            const hud = document.querySelector('#game-screen .game-hud');
            if (hud) document.documentElement.style.setProperty('--hud-h', hud.offsetHeight + 'px');
        }
        window.addEventListener('resize', function () {
            if (document.body.classList.contains('in-game')) seatMuteBtn();
        });

        /* ====================================================================
           sec.12 FEEDBACK TOGGLE - accessible, default OFF
           ==================================================================== */
        function toggleFeedback() {
            showFeedbackOnWrong = !showFeedbackOnWrong;
            const el = document.getElementById('feedback-toggle');
            el.classList.toggle('on', showFeedbackOnWrong);
            el.setAttribute('aria-checked', showFeedbackOnWrong ? 'true' : 'false');
        }

        /* ====================================================================
           START
           ==================================================================== */
        function startGame() {
            if (!POOL_AUDIT.ok) { console.error('[Ch1 G1] refusing to start: pool integrity failed'); return; }
            if (!DRAW_AUDIT.ok) { console.error('[Ch1 G1] refusing to start: draw audit failed (sec.25)'); return; }
            session = buildSession();
            if (session.rounds.length < 1) return;
            currentRound = 0;
            firstTryCorrect = 0;
            displayPoints = 0;
            currentStreak = 0;
            storefronts = { "Proprietorship": 0, "Partnership": 0, "Corporation": 0 };
            waveCardShown = [];
            answerLocked = false;
            advanceTokenLive = null;
            /* sec.25-quater class 5: re-rolled ONCE per session so the avatar
               sequence varies between plays while staying a function of the
               round index alone - never of the answer. */
            avatarOffset = Math.floor(Math.random() * AVATAR_ROSTER.length);
            nameOffset = Math.floor(Math.random() * NAME_ROSTER_M.length);
            hideWrongFeedback();
            showScreen('game-screen');
            updateDisplay();
            showStreakFeedback();
            renderBeat();
        }

        function updateDisplay() {
            document.getElementById('score-display').textContent = displayPoints;
            document.getElementById('round-display').textContent =
                (currentRound + 1) + '/' + session.rounds.length;
        }
        function getStreakBonus(streak) { if (streak <= 1) return 0; if (streak === 2) return 1; if (streak === 3) return 2; if (streak === 4) return 3; return 4; }
        function resetStreak() { currentStreak = 0; showStreakFeedback(); }
        function showStreakFeedback() {
            const ind = document.getElementById('streak-indicator');
            if (currentStreak >= 2) { ind.classList.add('active'); document.getElementById('streak-count').textContent = currentStreak; }
            else { ind.classList.remove('active'); }
        }

        /* ====================================================================
           RENDER - a beat is either the wave's concept card or a graded round.
           ==================================================================== */
        function renderBeat() {
            const round = session.rounds[currentRound];
            if (!round) { showResults(); return; }
            const wi = round.waveIndex;
            const isFirstOfWave = (currentRound === 0) || (session.rounds[currentRound - 1].waveIndex !== wi);
            if (wi < WAVES.length && isFirstOfWave && !waveCardShown[wi]) {
                waveCardShown[wi] = true;
                renderWaveCard(wi);
                return;
            }
            renderRound();
        }

        /* The teach beat. Ungraded by construction: it touches no graded value. */
        function renderWaveCard(wi) {
            answerLocked = true;          /* no answer surface exists on a card beat */
            mintRoundToken();
            /* sec.23-bis: a card beat has nothing to answer, so RENDER is its
               resolution - the one case where the permit is legal at paint time. */
            const token = mintAdvanceToken();
            const w = WAVES[wi];
            const rows = ENTITIES.map(function (e) {
                const m = ENTITY_META[e];
                return '<div class="wave-row wr-' + m.cls + '">' +
                       '<span class="wr-tag">' + escapeHtml(e) + '</span>' +
                       '<span class="wr-text">' + escapeHtml(w.rows[e]) + '</span></div>';
            }).join('');
            document.getElementById('game-area').innerHTML =
                renderStorefronts() +
                '<div class="wave-card">' +
                    '<div class="wave-eyebrow">Wave ' + (wi + 1) + ' of ' + (WAVES.length + 1) + ' &middot; concept card</div>' +
                    '<h3>' + escapeHtml(w.name) + '</h3>' +
                    '<p class="wave-lead">' + escapeHtml(w.lead) + '</p>' +
                    '<div class="wave-rows">' + rows + '</div>' +
                    '<div class="wave-takeaway"><strong>Takeaway:</strong> ' + escapeHtml(w.takeaway) + '</div>' +
                    '<div class="wave-card-footer">' +
                        '<button class="btn" data-action="dismiss-wave-card" data-token="' + token + '">GOT IT &#9654;</button>' +
                    '</div>' +
                '</div>';
            window.scrollTo(0, 0);
        }

        function dismissWaveCard(token) {
            armAdvanceGhostShield();   // A78-geo: arm from the CONTINUE contact, before the new round paints
            if (!consumeAdvanceToken(token)) return;   /* sec.23 advance-path lock */
            renderRound();
        }

        function renderStorefronts() {
            return '<div class="storefronts" id="storefronts">' + ENTITIES.map(function (e) {
                const m = ENTITY_META[e];
                const level = storefronts[e];
                const build = level === 0 ? '&middot;' : new Array(level + 1).join(m.build);
                return '<div class="storefront sf-' + m.cls + '" id="sf-' + m.cls + '">' +
                       '<div class="sf-build">' + build + '</div>' +
                       '<div class="sf-name">' + escapeHtml(e) + '</div>' +
                       '<div class="sf-count">' + level + ' won</div>' +
                       '</div>';
            }).join('') + '</div>';
        }

        function renderRound() {
            answerLocked = false;      /* sec.23: the ONLY release point for the answer lock */
            const token = mintRoundToken();   /* answer identity only - clears the advance permit */
            const round = session.rounds[currentRound];
            const item = round.item;
            const isConcept = (round.form === 'concept');
            const w = round.waveIndex < WAVES.length ? WAVES[round.waveIndex] : null;
            const eyebrow = w
                ? 'Wave ' + (round.waveIndex + 1) + ' &middot; ' + escapeHtml(w.name)
                : 'Final wave &middot; everything mixed, no card';
            /* sec.25-quater class 5, second channel: the cast name is recast by
               position. step1 text carries no cast name (audited: 0 of 100). */
            const promptText = isConcept
                ? escapeHtml(item.step1.question)
                : escapeHtml(recastNames(item.step2.scenario, currentRound));
            /* sec.25-quater class 5: the glyph is a function of the ROUND INDEX,
               never of the item - see AVATAR_ROSTER. item.step2.avatar is
               authored data and is deliberately not read here. */
            const avatarGlyph = AVATAR_ROSTER[(currentRound + avatarOffset) % AVATAR_ROSTER.length];
            const avatar = isConcept ? '' : '<div class="question-avatar" aria-hidden="true">' + escapeHtml(avatarGlyph) + '</div>';
            const ask = isConcept ? 'Which business type?' : 'Which entity fits this business?';
            const hint = w ? w.takeaway : 'Owners, debts, tax, starting up, lifetime - one of the five decides it.';

            document.getElementById('game-area').innerHTML =
                renderStorefronts() +
                '<div class="question-card">' +
                    '<div class="question-eyebrow">' + eyebrow + '</div>' +
                    avatar +
                    '<p class="question-text">' + promptText + '</p>' +
                    '<div class="hint-bubble" id="hint-bubble">' + escapeHtml(hint) + '</div>' +
                '</div>' +
                '<div class="player-response">' +
                    '<div class="entity-buttons">' + ENTITIES.map(function (e) {
                        const m = ENTITY_META[e];
                        return '<button class="entity-btn eb-' + m.cls + '" data-entity="' + escapeHtml(e) + '">' +
                               escapeHtml(m.icon) + ' ' + escapeHtml(e) +
                               '<span class="eb-sub">' + escapeHtml(m.sub) + '</span></button>';
                    }).join('') + '</div>' +
                    '<p class="sr-only">' + ask + '</p>' +
                '</div>';
            updateDisplay();
            /* token is carried by the round; the handler reads currentRoundToken */
            void token;
        }

        /* ====================================================================
           GRADED HANDLER
           ==================================================================== */
        function selectEntity(chosen) {
            if (advanceGhostShielded()) return;   // A78-geo — ghost tap from CONTINUE, and only under that finger
            if (answerLocked) return;      /* sec.23 synchronous tap-lock - FIRST statement */
            answerLocked = true;
            const token = currentRoundToken;
            const round = session.rounds[currentRound];
            if (!round) return;
            const item = round.item;
            const correct = round.form === 'concept' ? item.step1.correctAnswer : item.step2.correctAnswer;
            /* Same recast as the prompt, and the same round index, so the name in
               the explanation always matches the name the student just read. */
            const explanation = round.form === 'concept'
                ? item.step1.explanation
                : recastNames(item.step2.explanation, currentRound);
            const isCorrect = (chosen === correct);

            playFeedback('tap');
            document.querySelectorAll('.entity-btn').forEach(function (btn) {
                const e = btn.dataset.entity;
                if (e === chosen) btn.classList.add(isCorrect ? 'correct' : 'incorrect');
                if (!isCorrect && e === correct) setTimeout(function () { btn.classList.add('correct'); }, 260);
            });

            recordAnswer(isCorrect, chosen, correct, explanation, token);
        }

        function recordAnswer(isCorrect, chosen, correct, explanation, token) {
            /* sec.23-bis: the round RESOLVES here. This is the ONLY mint point for
               the advance permit on a graded beat - renderRound() must never mint
               one, or tap 1 advances and the fresh paint hands tap 2 another. */
            token = mintAdvanceToken();
            if (isCorrect) {
                /* GRADED. One submission per round (the lock guarantees it), so this
                   IS the first try. No bonus, no clamp, nothing else feeds the grade. */
                firstTryCorrect++;
                /* DISPLAY ONLY from here down. */
                currentStreak++;
                displayPoints += POINTS_PER_ROUND + getStreakBonus(currentStreak);
                growStorefront(correct);
                playFeedback('success');
                showStreakFeedback();
                updateDisplay();
                setTimeout(function () { advanceRound(token); }, 900);
            } else {
                resetStreak();
                playFeedback('error');
                updateDisplay();
                if (showFeedbackOnWrong) {
                    /* sec.12: wrong answers ONLY. The card waits for CONTINUE.
                       Three arguments exactly - the locked sec.12.3 interface.
                       The advance permit reaches the button through
                       advanceTokenLive, which mintAdvanceToken() has just set. */
                    showWrongFeedback(chosen, correct, explanation);
                } else {
                    setTimeout(function () { advanceRound(token); }, 900);
                }
            }
        }

        /* DISPLAY ONLY - the storefronts are the ruled visual payoff and touch
           nothing graded. */
        function growStorefront(entity) {
            if (storefronts[entity] === undefined) return;
            storefronts[entity]++;
            const m = ENTITY_META[entity];
            const el = document.getElementById('sf-' + m.cls);
            if (!el) return;
            const build = new Array(storefronts[entity] + 1).join(m.build);
            const buildEl = el.querySelector('.sf-build');
            const countEl = el.querySelector('.sf-count');
            if (buildEl) buildEl.textContent = build;
            if (countEl) countEl.textContent = storefronts[entity] + ' won';
            el.classList.remove('grew');
            void el.offsetWidth;
            el.classList.add('grew');
            playFeedback('grow');
        }

        /* ====================================================================
           sec.12 WRONG-ANSWER OVERLAY - three elements, in order.
           A correct answer NEVER reaches this function.
           ==================================================================== */
        function showWrongFeedback(studentAnswer, correctAnswer, explanation) {
            document.getElementById('your-answer-text').textContent = studentAnswer;
            document.getElementById('correct-answer-text').textContent = correctAnswer;
            document.getElementById('explanation-text').textContent = explanation;
            const btn = document.getElementById('wrong-feedback-continue');
            btn.dataset.token = String(advanceTokenLive);
            document.getElementById('wrong-feedback-overlay').classList.add('active');
            btn.focus();
        }
        function hideWrongFeedback() {
            document.getElementById('wrong-feedback-overlay').classList.remove('active');
        }
        function dismissWrongFeedback(token) {
            armAdvanceGhostShield();   // A78-geo: arm from the CONTINUE contact, before the new round paints
            if (!consumeAdvanceToken(token)) return;   /* sec.23 advance-path lock */
            hideWrongFeedback();
            goNext();
        }

        /* The single advance path for the graded surface. */
        function advanceRound(token) {
            if (!consumeAdvanceToken(token)) return;   /* sec.23 advance-path lock */
            goNext();
        }

        /* The one place the session moves forward. */
        function goNext() {
            currentRound++;
            if (currentRound < session.rounds.length) { updateDisplay(); renderBeat(); return false; }
            showResults();
            return true;
        }

        /* ====================================================================
           RESULTS - sec.16.3-bis. The graded percentage is first-try correct over
           rounds played. displayPoints is not in this sum, and there is no clamp:
           an accuracy ratio can never exceed its own maximum.
           ==================================================================== */
        /* ★ A205/A184 - THE ONE GRADED FORMULA, and it is used by BOTH LMS write
           sites (showResults and scormSafetyFinish) so the two can never drift
           apart. First-try correct over the FULL session denominator: an abandoned
           attempt is measured against the whole game, not against how far the
           student happened to get. */
        function gradedPct() {
            const total = session.rounds.length;
            return total > 0 ? Math.round((firstTryCorrect / total) * 100) : 0;
        }

        function showResults() {
            showScreen('results-screen');
            hideWrongFeedback();
            const total = session.rounds.length;
            if (total !== TOTAL_GRADED) {
                console.error('[Ch1 G1] graded denominator drifted to ' + total + ', expected ' + TOTAL_GRADED);
            }
            const pct = gradedPct();
            document.getElementById('final-score').textContent = pct + '%';
            document.getElementById('correct-count').textContent = firstTryCorrect + '/' + total;
            document.getElementById('points-total').textContent = displayPoints;

            /* A197 + A113 + A200 + A201 (David, 2026-08-05) - EXACTLY THREE RUNGS.
               THREE STARS REQUIRE ZERO ERRORS (A113): the top band is the CONDITION
               firstTryCorrect === total, never a percentage - at 20 rounds
               `pct >= 95` printed three stars and "Every storefront earned!" for 19
               of 20, i.e. one real mistake presented as perfection. The rule is the
               identity, so it stays honest if the round count moves.
               TWO STARS ARE NOW ANY PASS (A197). The old middle band was `pct >= 80`,
               which handed 10 of 13 (77%) a single star; A197 rules that harsh and
               sets the two-star floor at A103's unchanged PASS_MARK. Keep the
               CONSTANT - A103 freezes the pass mark and PASS_MARK is how it is
               expressed, so 60 is never inlined here.
               ONE STAR IS THE FLOOR (A200). The old fall-through awarded ZERO stars
               - measured on this build at 54% and at 0% - and there is no zero-star
               band anywhere in the fleet any more: a run that reaches this screen
               played it through and earns a star. `stars` therefore initialises to 1.
               A201: ONE ladder drives BOTH surfaces - `stars` feeds the star loop
               below and `msg` feeds #results-message - so the words can never
               disagree with the stars. The old FOUR messages collapse to three; the
               two passing messages ("Strong..." at 80+ and "Passed!" at 60+) merge.
               WARNING: THE WORDING IS AN A104 DRAFT awaiting David's sign-off.
               GRADE UNTOUCHED: pct, #pass-status below and SCORM.setScore(pct) all
               still turn on PASS_MARK exactly as before. This is praise only. */
            let stars = 1, msg = 'Keep going - reread the concept card at the top of each wave.';
            if (total > 0 && firstTryCorrect === total) { stars = 3; msg = '\uD83C\uDFC5 Every storefront earned!'; }
            else if (pct >= PASS_MARK) { stars = 2; msg = '\uD83D\uDC4F Passed - you can tell the three business forms apart.'; }
            document.getElementById('results-message').textContent = msg;
            for (let i = 1; i <= 3; i++) {
                const el = document.getElementById('star-' + i);
                el.textContent = i <= stars ? '\u2605' : '\u2606';
                el.classList.toggle('earned', i <= stars);
            }
            const status = document.getElementById('pass-status');
            status.textContent = pct >= PASS_MARK ? '\u2705 PASSED' : '\u274C NOT YET PASSED';
            status.style.color = pct >= PASS_MARK ? 'var(--color-success)' : 'var(--color-error)';
            status.style.background = pct >= PASS_MARK ? '#ECFDF5' : '#FEE2E2';
            status.style.border = pct >= PASS_MARK ? '3px solid var(--color-success)' : '3px solid var(--color-error)';
            SCORM.setScore(pct, false);   /* a finished run - may record 'passed' */
        }

        function showReadyScreen() { showScreen('ready-screen'); }

        /* sec.16.5 canonical exit handler */
        function exitGame() {
            // A228 / A223 (David, 2026-08-06) -- SAVE BEFORE TERMINATING.
            // Until this line exitGame() called finish() with no save, so the student who
            // pressed the button labelled EXIT TO COURSE lost every answer they had banked,
            // while the student who simply closed the tab kept theirs. That asymmetry is the
            // defect: the polite door punished the better-behaved student.
            // ⚠ THE GUARD IS ON THE GRADED QUANTITY, NEVER ON A PROGRESS COUNTER. A counter
            // advanced inside a setTimeout lags the grade, so a student who answers round 1
            // correctly and leaves inside the feedback pause would be recorded as having done
            // nothing; D194 measured that class at 74 of 74 games. `> 0` is also what keeps
            // A190: a zero-correct abandon writes NOTHING AT ALL, never an explicit 0,
            // because a 0 in a gradebook reads as a failed attempt and no attempt was made.
            // ⚠ CLONERS: this expression is a COPY of the graded computation in
            // scormSafetySave(). If you change how this game is scored, change BOTH.
            const exitPartialPct = gradedPct();
            if (exitPartialPct > 0) SCORM.setPartialScore(exitPartialPct);
            SCORM.finish();
            if (window.parent && window.parent !== window) window.parent.postMessage('courseExit', '*');
            /* A307 (David, 2026-08-12) - THE EXIT BUTTON MUST NEVER BE A DEAD BUTTON.
               window.close() stays as a BEST-EFFORT FIRST ATTEMPT: it is correct where
               it is permitted, and Blackboard launches the module in a NEW WINDOW, so
               there it works. Moodle embeds the module in the SAME TAB, where the
               browser blocks window.close() - David pressed this button in Moodle and
               nothing visible happened. The old `setTimeout(history.back, 500)`
               fallback is GONE: inside an LMS frame `back` goes nowhere, and it also
               DESTROYED the confirmation screen half a second after drawing it. FIRED
               on the pre-edit build of this file (msedge + scripts/scorm_reject_shim.py,
               13 of 13 correct, the real EXIT TO COURSE button): the document navigated
               to about:blank within 2 s of the click and NO screen was left active. */
            try { window.close(); } catch (e) {}
            showExitConfirmation(exitPartialPct > 0 || SCORM.wroteScore);
        }

        /* A307 - the plain confirmation. ESL-simple: short sentences, no
           abbreviations, no unexplained words, and it NEVER claims a score the game
           did not send. `saved` is a MEASUREMENT: SCORM.wroteScore is set true only
           where an LMSSetValue for cmi.core.score.raw was actually issued, and
           exitPartialPct > 0 covers the run whose honest score was already banked at
           the same value by an earlier write (the best-score guard then refuses a
           second one, so the flag alone would under-report). A zero-correct abandon
           writes nothing at all under A190 - fired on this file, and the accepted-call
           log for it contains no score.raw at all - so that student gets the second
           message, not the first. */
        function showExitConfirmation(saved) {
            hideWrongFeedback();
            /* ⚠ THE CONFIRMATION MUST NOT BE STOLEN BACK BY A PENDING TIMER. A student
               who answers the last story correctly and exits during the 900 ms
               feedback pause still has advanceRound() -> goNext() -> showResults() in
               flight, and showResults() calls showScreen('results-screen'). Before this
               change that did not matter, because exitGame() navigated the document
               away 500 ms after the click. Now that the page stays put, the results
               screen would replace the confirmation. The latch lives in showScreen(),
               the sole screen switcher, so one line closes every route in.
               ⚠ HONEST NOTE ON REACHABILITY: this game's ONLY exit control is the
               EXIT TO COURSE button on the results screen (l.704) - there is no header
               ✕ inside #game-screen - so that race is not reachable through this
               game's UI today. The latch is fired directly instead (see the report),
               and it is what makes this file already correct the moment an in-game
               exit control is added. */
            hasExited = true;
            const body = document.getElementById('exit-body');
            if (body) {
                body.innerHTML = saved
                    ? '<p class="exit-lead">Your work is saved.</p>' +
                      '<p>Your score has been sent to your course.</p>' +
                      '<p>You can now close this page. It is safe to do this.</p>'
                    : '<p class="exit-lead">Nothing new was saved this time.</p>' +
                      '<p>You did not answer a question correctly, so there was no new score to send. Any score you saved before is still safe.</p>' +
                      '<p>You can now close this page. You can play this game again later.</p>';
            }
            showScreen('exit-screen');
            try { document.getElementById('exit-title').focus(); } catch (e) {}
        }
        /* ★ A205 / A184 (David, 2026-08-05). THE SAFETY NET NOW SAVES.
           The old body was a bare SCORM.finish(), justified only by an in-file
           comment - "a mid-session exit must NOT submit a partial score" - which was
           never a recorded ruling, and this game carries none of the D144/A189
           carve-out markers. Four first-try-correct of thirteen therefore left NO
           trace at all. A184 is the standing rule: record the honest partial over the
           FULL denominator, with 'incomplete'.

           ★ WHY THE GUARD IS `firstTryCorrect > 0` - it has to satisfy TWO rulings at
           once. A190 says a ZERO-CORRECT abandon must write NOTHING, and zero-correct
           is literally firstTryCorrect === 0. A184 says an honest partial must never
           be suppressed, and a CORRECTNESS guard can break that in a game that awards
           part marks (CH1-G38's lesson). It cannot break it here, because this game
           has NO partial credit: every round is one binary first-try decision
           (`answerLocked` guarantees a single submission per round), firstTryCorrect
           is incremented in exactly ONE place, by exactly one, only on isCorrect, and
           it carries no bonus or streak term - displayPoints is the only value the
           streak touches. So `firstTryCorrect > 0` and `gradedPct() > 0` are the same
           condition in this file, and the guard satisfies both rulings.

           ⛔ A218 / A228 (2026-08-09) - THE ABANDON WRITE IS setPartialScore(), NEVER
           setScore(). The old line was
               SCORM.setScore(gradedPct(), currentRound < session.rounds.length);
           and it was CORRECT ON THE DAY: `partial` computes false only where
           goNext() has already called showResults(), so the fire harness could
           not make it bank a false pass. That is exactly the protection A218
           refuses to accept. Its ruling is STRUCTURAL - no game may call
           setScore from its page-closing handler - because shape A "is protected
           solely by an author picking the right method name". PROVEN on this
           file: drop that second argument and `!partial` opens the pass branch;
           fired at 8 first-try-correct of 13 (62%), a real `pagehide`, and the
           gradebook took score.raw '62' / lesson_status 'passed' for a run the
           student walked out of. setPartialScore() carries no such argument and
           cannot reach 'passed' however it is called.

           A run that already reached the results screen is NOT abandoned, and
           nothing is lost by the change: showResults() has already set bestScore
           to the same value, so setPartialScore()'s `!(s > this.bestScore)`
           guard returns and the 'passed' it recorded stands untouched.

           ⛔ A164 / A188 / A208 (David, 2026-08-05) - TWO HANDLERS, NOT ONE.
               `pagehide`     -> scormSafetySave()   : writes the honest partial, NEVER finishes.
               `beforeunload` -> scormSafetySave() : saves ONLY, and LEAVES THE ATTEMPT OPEN (A317, David 2026-08-16 -- only EXIT ends it).

           FIRED ON THIS FILE AT HEAD (msedge, `scripts/scorm_reject_shim.py`, the shim
           that REFUSES writes after LMSFinish exactly as a real SCORM 1.2 LMS does,
           2026-08-05): 2 of 13 rounds correct -> a real `pagehide` (an iOS tab switch,
           which is NOT an exit) -> the student comes BACK and finishes all 13 at 100%.
           The results screen read 100% / PASSED / three stars and the LMS was left
           holding score.raw '15' / 'incomplete'. ⚠ Not one further LMS call was even
           ATTEMPTED - the shim's rejected log was EMPTY - because the pagehide handler
           had reached SCORM.finish(), which sets `finished = true`, and setScore() opens
           with `if (!this.initialized || this.finished) return`. The loss is SILENT: no
           rejected write to find in a log, only an absence. A genuine completed pass,
           destroyed. That is also why the shim matters: a permissive shim accepts the
           late write and reports the run as having reached the LMS.

           A188 SPLITS the fix per game, and THIS GAME IS THE SAVE-ONLY SIDE. ⚠ The A208
           register row records that "CH1-G1's agent already identified its own game as
           the plain-removal shape" - that was true of the file BEFORE A205/A184 landed,
           when the safety net was a bare SCORM.finish() with nothing to save. It is no
           longer true: the guarded partial write below is an honest A184 partial, so
           removing the listener outright would now DELETE a save. A188 names that mirror
           hazard explicitly, and the partial write MOVES into the save-only branch.

           ⚠ THE COST, ACCEPTED BY A164: a tab genuinely closed on iOS fires `pagehide`
           and often not `beforeunload`, so that session ends with no LMSFinish and no
           cmi.core.session_time. The SCORE is never at risk - setScore() commits inside
           the same block (register O12). Losing time-on-task is a far smaller harm than
           destroying a completed pass. */
        function scormSafetySave() {
            if (firstTryCorrect > 0 && !SCORM.finished) {
                SCORM.setPartialScore(gradedPct());   /* A218: the abandon path, structurally unable to write 'passed' */
            }
        }
        function scormSafetyFinish() {
            scormSafetySave();
            SCORM.finish();
        }

        /* ====================================================================
           ACTION ROUTER
           ==================================================================== */
        document.addEventListener('click', function (e) {
            const el = e.target.closest('[data-action]');
            if (!el) return;
            const action = el.dataset.action;
            if      (action === 'show-learning')       { showScreen('learning-screen'); }
            else if (action === 'show-intro')          { showScreen('intro-screen'); }
            else if (action === 'show-ready')          { showReadyScreen(); }
            else if (action === 'start-game')          { startGame(); }
            else if (action === 'play-again')          { showReadyScreen(); }
            else if (action === 'exit')                { exitGame(); }
            else if (action === 'toggle-mute')         { toggleMute(); }
            else if (action === 'toggle-feedback')     { toggleFeedback(); }
            else if (action === 'dismiss-feedback')    { dismissWrongFeedback(parseInt(el.dataset.token, 10)); }
            else if (action === 'dismiss-wave-card')   { dismissWaveCard(parseInt(el.dataset.token, 10)); }
            else if (action === 'show-hint')           {
                const bubble = document.getElementById('hint-bubble');
                if (bubble) bubble.classList.toggle('active');
            }
        });

        /* sec.12.4a keyboard-operable toggle */
        document.getElementById('feedback-toggle').addEventListener('keydown', function (e) {
            if (e.key === ' ' || e.key === 'Enter' || e.key === 'Spacebar') { e.preventDefault(); toggleFeedback(); }
        });

        /* Delegated graded-tap handler */
        document.getElementById('game-area').addEventListener('click', function (e) {
            const btn = e.target.closest('.entity-btn[data-entity]');
            if (!btn) return;
            selectEntity(btn.dataset.entity);
        });

        /* ⭐ A317 (David, 2026-08-16): the tab close SAVES but must NOT end the
               attempt -- a student who nearly leaves, then carries on and
               finishes strongly, was keeping the lower part-way mark.
               Only exitGame() ends it now. scormSafetyFinish() below is
               RETAINED AND UNREFERENCED on purpose; exitGame() already
               saves then finishes inline. Do not re-bind this to it. */
        window.addEventListener('beforeunload', scormSafetySave);
        window.addEventListener('pagehide', scormSafetySave);   /* A164/A188/A208: SAVE ONLY - never LMSFinish */

        /* Harness hooks - read-only, used by the build verification pass. */
        try {
            window.__G1 = {
                get state() {
                    return {
                        currentRound: currentRound, firstTryCorrect: firstTryCorrect,
                        displayPoints: displayPoints, total: session.rounds.length,
                        answerLocked: answerLocked, advanceTokenLive: advanceTokenLive,
                        storefronts: storefronts
                    };
                },
                answers: function () { return session.rounds.map(function (r) { return r.answer; }); },
                forms: function () { return session.rounds.map(function (r) { return r.form; }); },
                select: function (entity) { selectEntity(entity); },
                buildSession: buildSession,
                setFeedback: function (on) { if (on !== showFeedbackOnWrong) toggleFeedback(); }
            };
        } catch (e) { /* no window (harness) */ }
    </script>
</body>

</html>