:root {
      --blue: #1d4ed8;
      --blue2: #2563eb;
      --navy: #0f172a;
      --ink: #1e293b;
      --muted: #64748b;
      --line: #dbe4f0;
      --soft: #f8fafc;
      --soft-blue: #eff6ff;
      --green: #15803d;
      --green-soft: #f0fdf4;
      --amber: #b45309;
      --amber-soft: #fffbeb;
      --purple: #7e22ce;
      --purple-soft: #faf5ff;
      --danger: #b91c1c;
      --shadow: 0 20px 50px rgba(15, 23, 42, .10);
      --radius: 18px;
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      color: var(--ink);
      background:
        radial-gradient(circle at 10% 0%, rgba(37,99,235,.08), transparent 28rem),
        linear-gradient(180deg, #ffffff 0, #f8fafc 46rem, #f1f5f9 100%);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      min-height: 100vh;
    }

    button, input { font: inherit; }
    button { cursor: pointer; }
    a { color: inherit; }

    .topbar {
      position: sticky;
      top: 0;
      z-index: 50;
      backdrop-filter: blur(14px);
      background: rgba(255,255,255,.90);
      border-bottom: 1px solid rgba(219,228,240,.9);
    }
    .topbar-inner {
      max-width: 1480px;
      margin: 0 auto;
      min-height: 64px;
      padding: 0 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
    }
    .brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
    .brand-mark {
      width: 36px; height: 36px; border-radius: 11px;
      display: grid; place-items: center;
      background: linear-gradient(135deg, var(--blue), #60a5fa);
      color: #fff; font-weight: 800; box-shadow: 0 8px 20px rgba(29,78,216,.22);
    }
    .brand-text { min-width: 0; }
    .brand-title { font-size: .92rem; font-weight: 800; color: var(--navy); white-space: nowrap; }
    .brand-sub { font-size: .72rem; color: var(--muted); margin-top: 1px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .top-actions { display: flex; align-items: center; gap: 8px; }
    .top-link, .ghost-btn {
      border: 1px solid var(--line);
      background: #fff;
      color: var(--ink);
      border-radius: 10px;
      padding: 9px 12px;
      text-decoration: none;
      font-weight: 700;
      font-size: .82rem;
      transition: .18s ease;
    }
    .top-link:hover, .ghost-btn:hover { border-color: #b7c7dc; transform: translateY(-1px); }

    .hero {
      max-width: 1480px;
      margin: 0 auto;
      padding: 48px 24px 26px;
      display: grid;
      grid-template-columns: minmax(0, 1.25fr) minmax(330px, .75fr);
      gap: 34px;
      align-items: end;
    }
    .eyebrow {
      display: inline-flex; align-items: center; gap: 8px;
      color: var(--blue); font-size: .78rem; font-weight: 900;
      text-transform: uppercase; letter-spacing: .08em;
      margin-bottom: 12px;
    }
    h1 {
      margin: 0;
      color: var(--navy);
      font-size: clamp(2.5rem, 5.2vw, 5.4rem);
      line-height: .94;
      letter-spacing: -.055em;
      max-width: 900px;
    }
    .hero-lead {
      max-width: 820px;
      color: #475569;
      font-size: clamp(1rem, 1.6vw, 1.25rem);
      line-height: 1.62;
      margin: 22px 0 0;
    }
    .hero-card {
      background: rgba(255,255,255,.96);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      padding: 22px;
      box-shadow: var(--shadow);
    }
    .hero-card-title { color: var(--navy); font-weight: 900; margin-bottom: 10px; }
    .hero-card p { margin: 0; color: #475569; line-height: 1.55; font-size: .92rem; }
    .hero-card strong { color: var(--blue); }

    .app-shell {
      max-width: 1480px;
      margin: 0 auto;
      padding: 0 24px 70px;
    }
    .layout {
      display: grid;
      grid-template-columns: 370px minmax(0,1fr);
      gap: 20px;
      align-items: start;
    }
    .panel {
      background: rgba(255,255,255,.97);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: 0 12px 32px rgba(15,23,42,.06);
    }
    .control-panel { position: sticky; top: 82px; overflow: hidden; }
    .panel-head { padding: 19px 20px 15px; border-bottom: 1px solid var(--line); }
    .panel-head h2 { margin: 0; color: var(--navy); font-size: 1.05rem; }
    .panel-head p { margin: 6px 0 0; color: var(--muted); font-size: .78rem; line-height: 1.45; }
    .control-body { padding: 18px 20px 20px; }

    .presets { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-bottom: 18px; }
    .preset {
      border: 1px solid var(--line); background: var(--soft); color: #334155;
      padding: 10px; border-radius: 11px; font-weight: 800; font-size: .76rem;
      text-align: left;
    }
    .preset:hover { border-color: #a9bee0; }
    .preset.active { border-color: #93b4ff; background: var(--soft-blue); color: var(--blue); }

    .field { margin: 16px 0; }
    .field-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 8px; }
    .field label { color: #334155; font-size: .78rem; font-weight: 800; }
    .value-chip { color: var(--blue); background: var(--soft-blue); border-radius: 999px; padding: 4px 8px; font-size: .73rem; font-weight: 900; }
    input[type="range"] { width: 100%; accent-color: var(--blue); }
    input[type="number"] {
      width: 100%; border: 1px solid var(--line); border-radius: 10px; padding: 10px 11px;
      color: var(--navy); background: #fff; font-weight: 800;
    }
    .mini-note { color: var(--muted); font-size: .70rem; line-height: 1.38; margin-top: 6px; }

    .role-strip {
      padding: 13px; margin: 18px 0; border-radius: 13px;
      background: #f8fafc; border: 1px solid var(--line);
    }
    .role-strip strong { display: block; color: var(--navy); font-size: .78rem; margin-bottom: 7px; }
    .role-strip span { display: block; color: #475569; font-size: .73rem; line-height: 1.5; }

    .primary-btn {
      width: 100%; border: 0; border-radius: 12px; padding: 13px 15px;
      background: linear-gradient(135deg, var(--blue), var(--blue2)); color: #fff;
      font-weight: 900; box-shadow: 0 10px 22px rgba(29,78,216,.22);
    }
    .secondary-btn {
      width: 100%; border: 1px solid var(--line); border-radius: 12px; padding: 11px 15px;
      background: #fff; color: #334155; font-weight: 800; margin-top: 8px;
    }

    .game-area { min-width: 0; }
    .score-grid {
      display: grid;
      grid-template-columns: repeat(5, minmax(0,1fr));
      gap: 10px;
      margin-bottom: 12px;
    }
    .score-card {
      background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 13px 14px;
      min-height: 84px; box-shadow: 0 8px 24px rgba(15,23,42,.04);
    }
    .score-label { font-size: .67rem; text-transform: uppercase; letter-spacing: .055em; color: var(--muted); font-weight: 900; }
    .score-value { margin-top: 8px; font-size: clamp(1.02rem, 2vw, 1.5rem); color: var(--navy); font-weight: 950; letter-spacing: -.03em; }
    .score-sub { margin-top: 2px; font-size: .65rem; color: #94a3b8; }

    .stage {
      overflow: hidden;
      min-height: 590px;
      position: relative;
    }
    .stage-top {
      padding: 20px 22px 18px;
      border-bottom: 1px solid var(--line);
      display: flex; align-items: flex-start; justify-content: space-between; gap: 16px;
    }
    .round-kicker { color: var(--blue); text-transform: uppercase; letter-spacing: .07em; font-weight: 950; font-size: .72rem; }
    .stage-title { color: var(--navy); margin: 4px 0 0; font-size: clamp(1.35rem,2.4vw,2.1rem); line-height: 1.08; letter-spacing: -.03em; }
    .stage-status { color: var(--muted); font-size: .75rem; text-align: right; white-space: nowrap; }

    .stage-body { padding: 22px; }
    .actors {
      display: grid;
      grid-template-columns: repeat(4, minmax(0,1fr));
      gap: 10px;
      margin-bottom: 18px;
    }
    .actor {
      border: 1px solid var(--line); background: var(--soft); border-radius: 14px; padding: 13px;
      transition: .2s ease; min-height: 103px;
    }
    .actor.active { border-color: #93b4ff; background: var(--soft-blue); box-shadow: 0 0 0 3px rgba(37,99,235,.08); transform: translateY(-2px); }
    .actor .icon { font-size: 1.25rem; }
    .actor .role { color: var(--muted); font-size: .64rem; font-weight: 900; text-transform: uppercase; letter-spacing: .06em; margin-top: 8px; }
    .actor .name { color: var(--navy); font-weight: 900; font-size: .88rem; margin-top: 2px; }
    .actor .detail { color: #64748b; font-size: .68rem; margin-top: 4px; line-height: 1.35; }

    .action-card {
      border: 1px solid #bfdbfe;
      background: linear-gradient(135deg,#eff6ff,#fff);
      border-radius: 17px;
      padding: 20px;
      position: relative;
      overflow: hidden;
    }
    .action-card:before {
      content: ""; position: absolute; right: -55px; top: -55px; width: 170px; height: 170px;
      border-radius: 50%; background: rgba(37,99,235,.06);
    }
    .action-label { color: var(--blue); font-weight: 950; text-transform: uppercase; letter-spacing: .07em; font-size: .69rem; }
    .action-text { color: var(--navy); font-weight: 850; font-size: clamp(1.05rem,1.8vw,1.36rem); line-height: 1.38; margin: 8px 0 0; max-width: 900px; position: relative; }
    .action-amount { color: var(--blue); white-space: nowrap; }
    .action-explain { color: #475569; margin: 9px 0 0; font-size: .83rem; line-height: 1.55; max-width: 900px; position: relative; }

    .flow {
      margin-top: 16px;
      display: grid;
      grid-template-columns: minmax(0,1fr) 54px minmax(0,1fr);
      gap: 8px;
      align-items: center;
    }
    .flow-node { border-radius: 13px; padding: 13px; border: 1px solid var(--line); background: #fff; }
    .flow-node .small { color: var(--muted); font-size: .65rem; text-transform: uppercase; font-weight: 900; letter-spacing: .05em; }
    .flow-node .big { color: var(--navy); font-size: .93rem; font-weight: 900; margin-top: 3px; }
    .flow-arrow { text-align: center; color: var(--blue); font-size: 1.6rem; font-weight: 900; }

    .delta-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
    .delta { border-radius: 999px; padding: 7px 10px; font-size: .70rem; font-weight: 900; border: 1px solid transparent; }
    .delta.up { color: var(--green); background: var(--green-soft); border-color: #bbf7d0; }
    .delta.flat { color: #475569; background: #f8fafc; border-color: var(--line); }
    .delta.shift { color: var(--purple); background: var(--purple-soft); border-color: #e9d5ff; }

    .teacher-prompt {
      margin-top: 15px; border-left: 4px solid #f59e0b; background: var(--amber-soft); border-radius: 0 12px 12px 0;
      padding: 12px 14px; color: #78350f; font-size: .78rem; line-height: 1.5;
    }
    .teacher-prompt strong { color: #92400e; }

    .nav-row { display: grid; grid-template-columns: 1fr 1.4fr; gap: 9px; margin-top: 18px; }
    .nav-btn { border-radius: 12px; padding: 12px 14px; font-weight: 900; border: 1px solid var(--line); background: #fff; color: #334155; }
    .nav-btn.next { border: 0; color: #fff; background: var(--blue); }
    .nav-btn:disabled { opacity: .35; cursor: default; }

    .ledger {
      margin-top: 12px;
      overflow: hidden;
    }
    .ledger-head { padding: 15px 18px; border-bottom: 1px solid var(--line); display: flex; justify-content: space-between; gap: 12px; align-items: center; }
    .ledger-head h3 { margin: 0; color: var(--navy); font-size: .93rem; }
    .ledger-head span { color: var(--muted); font-size: .7rem; }
    .ledger-scroll { overflow-x: auto; }
    table { width: 100%; border-collapse: collapse; min-width: 780px; }
    th, td { padding: 10px 13px; border-bottom: 1px solid #edf2f7; text-align: right; font-size: .71rem; }
    th { color: #64748b; font-weight: 900; text-transform: uppercase; letter-spacing: .04em; background: #fbfdff; }
    th:first-child, td:first-child, th:nth-child(2), td:nth-child(2) { text-align: left; }
    td { color: #334155; }
    tr.current td { background: #eff6ff; color: #1e3a8a; font-weight: 800; }

    .debrief {
      margin-top: 20px; padding: 24px;
      display: grid; grid-template-columns: minmax(0,1.05fr) minmax(310px,.95fr); gap: 20px;
    }
    .debrief h2 { color: var(--navy); margin: 0; font-size: 1.35rem; letter-spacing: -.025em; }
    .debrief p { color: #475569; line-height: 1.58; font-size: .86rem; }
    .question-list { display: grid; gap: 8px; margin-top: 14px; }
    .question { padding: 11px 12px; border-radius: 11px; border: 1px solid var(--line); background: var(--soft); font-size: .78rem; color: #334155; font-weight: 700; }
    .formula-box { border-radius: 15px; background: var(--navy); color: #e2e8f0; padding: 18px; }
    .formula-box .label { color: #93c5fd; font-weight: 900; text-transform: uppercase; letter-spacing: .06em; font-size: .67rem; }
    .formula { font-size: clamp(1.35rem,3vw,2.1rem); font-weight: 950; color: #fff; margin: 10px 0 8px; letter-spacing: -.04em; }
    .formula-box p { color: #cbd5e1; margin: 0; font-size: .76rem; }
    .result-line { display: flex; justify-content: space-between; gap: 12px; border-top: 1px solid #334155; margin-top: 14px; padding-top: 12px; font-size: .78rem; }
    .result-line strong { color: #fff; }

    .footer { text-align: center; color: #94a3b8; font-size: .72rem; padding: 28px 18px 38px; }

    .projector .control-panel, .projector .ledger, .projector .debrief, .projector .hero-card { display: none; }
    .projector .layout { grid-template-columns: 1fr; }
    .projector .hero { grid-template-columns: 1fr; padding-top: 24px; }
    .projector .hero-lead { max-width: 1100px; }
    .projector .stage { min-height: 66vh; }
    .projector .score-value { font-size: clamp(1.35rem,3vw,2.15rem); }
    .projector .stage-title { font-size: clamp(1.8rem,4vw,3.2rem); }
    .projector .action-text { font-size: clamp(1.35rem,2.6vw,2.2rem); }

    @media (max-width: 1050px) {
      .hero { grid-template-columns: 1fr; }
      .layout { grid-template-columns: 1fr; }
      .control-panel { position: static; }
      .score-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
    }
    @media (max-width: 720px) {
      .topbar-inner, .hero, .app-shell { padding-left: 14px; padding-right: 14px; }
      .top-link { display: none; }
      .hero { padding-top: 30px; }
      h1 { font-size: clamp(2.7rem,15vw,4.3rem); }
      .score-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
      .actors { grid-template-columns: repeat(2,minmax(0,1fr)); }
      .stage-top { flex-direction: column; }
      .stage-status { text-align: left; }
      .flow { grid-template-columns: 1fr; }
      .flow-arrow { transform: rotate(90deg); }
      .debrief { grid-template-columns: 1fr; }
      .presets { grid-template-columns: 1fr; }
    }

    @media print {
      .topbar, .top-actions, .nav-row, .control-panel, .ledger { display: none !important; }
      body { background: #fff; }
      .hero { padding: 20px; grid-template-columns: 1fr; }
      .hero-card { box-shadow: none; }
      .layout { display: block; }
      .panel, .score-card { box-shadow: none; break-inside: avoid; }
      .stage { min-height: 0; }
      .app-shell { padding: 0 20px; }
    }