:root {
  color-scheme: light dark;
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --text: #111827;
  --muted: #64748b;
  --border: #e2e8f0;
  --primary: #111827;
  --primary-contrast: #ffffff;
  --accent: #2563eb;
  --success: #15803d;
  --success-soft: #dcfce7;
  --danger: #b91c1c;
  --danger-soft: #fee2e2;
  --warning: #b45309;
  --warning-soft: #fef3c7;
  --shadow: 0 12px 30px rgba(15, 23, 42, .08);
  --radius: 18px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #070b13;
    --surface: #0f172a;
    --surface-2: #111827;
    --text: #f8fafc;
    --muted: #94a3b8;
    --border: #243247;
    --primary: #f8fafc;
    --primary-contrast: #111827;
    --accent: #60a5fa;
    --success: #4ade80;
    --success-soft: #12331f;
    --danger: #f87171;
    --danger-soft: #3a1717;
    --warning: #fbbf24;
    --warning-soft: #392b12;
    --shadow: 0 12px 30px rgba(0,0,0,.25);
  }
}
* { box-sizing: border-box; }
html { background: var(--bg); }
body { margin: 0; min-height: 100vh; background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
button, input, select { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }
#app-shell { min-height: 100vh; padding-bottom: 88px; }
.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; padding: max(14px, env(safe-area-inset-top)) 18px 12px; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(18px); border-bottom: 1px solid color-mix(in srgb, var(--border) 70%, transparent); }
.topbar h1 { font-size: 20px; line-height: 1.1; margin: 2px 0 0; }
.eyebrow { color: var(--muted); font-size: 11px; letter-spacing: .09em; text-transform: uppercase; font-weight: 700; }
.app-content { width: min(100%, 920px); margin: 0 auto; padding: 16px; }
.bottom-nav { position: fixed; z-index: 30; left: 50%; transform: translateX(-50%); bottom: 0; width: min(100%, 920px); display: grid; grid-template-columns: repeat(5,1fr); padding: 8px 8px max(8px, env(safe-area-inset-bottom)); background: color-mix(in srgb, var(--surface) 94%, transparent); backdrop-filter: blur(18px); border-top: 1px solid var(--border); }
.nav-btn { border: 0; background: transparent; color: var(--muted); min-height: 58px; border-radius: 14px; display: grid; place-items: center; gap: 2px; cursor: pointer; }
.nav-btn span { font-size: 20px; line-height: 1; }
.nav-btn small { font-size: 10px; font-weight: 700; }
.nav-btn.active { color: var(--text); background: var(--surface-2); }
.hidden { display: none !important; }
.icon-btn { width: 42px; height: 42px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); color: var(--text); font-size: 24px; cursor: pointer; box-shadow: var(--shadow); }
.hero { background: linear-gradient(145deg, var(--surface), var(--surface-2)); border: 1px solid var(--border); border-radius: 24px; padding: 20px; box-shadow: var(--shadow); }
.hero h2 { margin: 0 0 8px; font-size: clamp(24px, 7vw, 34px); line-height: 1.05; }
.hero p { margin: 0; color: var(--muted); line-height: 1.5; }
.countdown { margin-top: 18px; display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.countdown strong { font-size: 30px; }
.badge, .chip { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--border); background: var(--surface-2); color: var(--muted); border-radius: 999px; padding: 6px 10px; font-size: 12px; font-weight: 700; }
.badge.guide { background: var(--warning-soft); color: var(--warning); border-color: color-mix(in srgb, var(--warning) 25%, var(--border)); }
.badge.generated { background: color-mix(in srgb, var(--accent) 12%, var(--surface)); color: var(--accent); }
.badge.reading { background: var(--success-soft); color: var(--success); }
.grid { display: grid; grid-template-columns: 1fr; gap: 12px; margin-top: 14px; }
@media (min-width: 680px) { .grid.two { grid-template-columns: repeat(2,1fr); } .grid.three { grid-template-columns: repeat(3,1fr); } }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); }
.card h3 { margin: 0 0 8px; font-size: 17px; }
.card p { color: var(--muted); line-height: 1.45; margin: 4px 0 0; }
.action-card { text-align: left; width: 100%; cursor: pointer; color: var(--text); }
.action-card:active { transform: scale(.99); }
.metric-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 8px; margin-top: 14px; }
.metric { border: 1px solid var(--border); background: var(--surface-2); border-radius: 15px; padding: 12px; }
.metric b { display: block; font-size: 20px; }
.metric span { color: var(--muted); font-size: 11px; }
.section-head { display: flex; justify-content: space-between; gap: 12px; align-items: flex-end; margin: 22px 2px 10px; }
.section-head h2 { margin: 0; font-size: 20px; }
.section-head p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.btn { border: 0; border-radius: 15px; min-height: 48px; padding: 11px 16px; font-weight: 800; cursor: pointer; }
.btn.primary { background: var(--primary); color: var(--primary-contrast); }
.btn.secondary { background: var(--surface); color: var(--text); border: 1px solid var(--border); }
.btn.accent { background: var(--accent); color: white; }
.btn.danger { background: var(--danger-soft); color: var(--danger); border: 1px solid color-mix(in srgb, var(--danger) 25%, transparent); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.progress-wrap { margin: 8px 0 16px; }
.progress-meta { display: flex; justify-content: space-between; gap: 10px; align-items: center; font-size: 12px; color: var(--muted); margin-bottom: 7px; }
.progress { height: 8px; border-radius: 999px; background: var(--border); overflow: hidden; }
.progress > div { height: 100%; background: var(--accent); border-radius: inherit; transition: width .25s ease; }
.question-card { min-height: 64vh; display: flex; flex-direction: column; }
.question-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 10px; flex-wrap: wrap; }
.question-text { font-size: clamp(20px, 6vw, 28px); line-height: 1.3; margin: 22px 0 18px; letter-spacing: -.01em; }
.options { display: grid; gap: 10px; }
.option { width: 100%; min-height: 58px; text-align: left; padding: 14px 16px; border-radius: 16px; border: 1px solid var(--border); background: var(--surface-2); color: var(--text); font-weight: 650; cursor: pointer; line-height: 1.35; }
.option:hover { border-color: color-mix(in srgb, var(--accent) 50%, var(--border)); }
.option.selected { outline: 2px solid var(--accent); border-color: transparent; }
.option.correct { background: var(--success-soft); color: var(--success); border-color: color-mix(in srgb, var(--success) 35%, var(--border)); }
.option.wrong { background: var(--danger-soft); color: var(--danger); border-color: color-mix(in srgb, var(--danger) 35%, var(--border)); }
.feedback { margin-top: 14px; padding: 14px; border-radius: 15px; line-height: 1.45; }
.feedback.ok { background: var(--success-soft); color: var(--success); }
.feedback.bad { background: var(--danger-soft); color: var(--danger); }
.feedback b { display: block; margin-bottom: 4px; }
.question-actions { margin-top: auto; padding-top: 16px; display: flex; gap: 8px; }
.question-actions .btn.primary { flex: 1; }
.passage { border: 1px solid var(--border); border-radius: 16px; background: var(--surface-2); padding: 15px; margin: 12px 0 4px; line-height: 1.6; color: var(--text); }
.passage h3 { margin: 0 0 8px; }
.topic-list { display: grid; gap: 10px; }
.topic-btn { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; background: var(--surface); border: 1px solid var(--border); color: var(--text); border-radius: 16px; padding: 14px; text-align: left; cursor: pointer; }
.topic-btn b { display: block; }
.topic-btn small { color: var(--muted); }
.accuracy { min-width: 54px; text-align: right; font-weight: 800; }
.accuracy.good { color: var(--success); }
.accuracy.mid { color: var(--warning); }
.accuracy.bad { color: var(--danger); }
.callout { padding: 14px; border-radius: 16px; border: 1px solid color-mix(in srgb, var(--accent) 20%, var(--border)); background: color-mix(in srgb, var(--accent) 8%, var(--surface)); }
.callout b { display: block; margin-bottom: 3px; }
.callout p { color: var(--muted); margin: 0; line-height: 1.45; }
.result-score { text-align: center; padding: 22px 0 10px; }
.result-score strong { display: block; font-size: 64px; line-height: 1; }
.result-score span { color: var(--muted); }
.bar-list { display: grid; gap: 12px; }
.bar-row { display: grid; grid-template-columns: minmax(110px,1fr) 2fr 48px; gap: 10px; align-items: center; font-size: 12px; }
.bar-track { height: 8px; background: var(--border); border-radius: 99px; overflow: hidden; }
.bar-fill { height: 100%; background: var(--accent); }
.error-code { display: inline-flex; align-items: center; justify-content: center; width: 28px; height: 28px; border-radius: 9px; font-weight: 900; background: var(--danger-soft); color: var(--danger); }
.error-item { display: grid; grid-template-columns: 36px 1fr; gap: 10px; align-items: start; }
.error-item h4 { margin: 1px 0 3px; }
.error-item p { margin: 0; font-size: 13px; color: var(--muted); }
.flash { padding: 16px; border-radius: 16px; border: 1px solid var(--border); background: var(--surface); }
.flash h3 { margin-top: 0; }
.flash ul { margin: 8px 0 0; padding-left: 18px; color: var(--muted); line-height: 1.65; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 16px; }
table { border-collapse: collapse; width: 100%; min-width: 480px; background: var(--surface); }
th, td { padding: 11px 12px; text-align: left; border-bottom: 1px solid var(--border); }
th { font-size: 12px; color: var(--muted); }
.timer { font-variant-numeric: tabular-nums; font-weight: 900; font-size: 14px; }
.timer.danger { color: var(--danger); }
.select { width: 100%; min-height: 48px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); color: var(--text); padding: 10px 12px; }
.inline-form { display: grid; grid-template-columns: 1fr; gap: 10px; }
@media (min-width:680px){ .inline-form { grid-template-columns: repeat(3,1fr); } }
.toast { position: fixed; left: 50%; transform: translateX(-50%); bottom: 92px; z-index: 100; background: var(--text); color: var(--bg); border-radius: 999px; padding: 10px 16px; font-size: 13px; font-weight: 700; opacity: 0; pointer-events: none; transition: opacity .2s; }
.toast.show { opacity: 1; }
.fav-btn { border: 1px solid var(--border); background: var(--surface); color: var(--muted); border-radius: 12px; width: 42px; height: 42px; cursor: pointer; font-size: 20px; }
.fav-btn.on { color: #f59e0b; }
.small { font-size: 12px; color: var(--muted); }
hr.sep { border: 0; border-top: 1px solid var(--border); margin: 18px 0; }
.source-note { font-size: 11px; color: var(--muted); margin-top: 8px; }
.empty { text-align: center; padding: 38px 16px; color: var(--muted); }