/* LearningHub — single stylesheet, no build step (NFR-13). */

/* ============================================================== 1. Tokens */

:root {
  color-scheme: dark;

  /* Surfaces, from furthest back to nearest front. */
  --bg: #0b0d12;
  --bg-glow: #141a2b;
  --surface: #141821;
  --surface-2: #1b2130;
  --surface-3: #232b3d;
  --border: #2a3243;
  --border-strong: #3a455d;

  --text: #eef1f7;
  --text-muted: #96a1b8;
  --text-faint: #8491ab;

  --accent: #6c8cff;
  --accent-2: #39d3bb;
  --accent-ink: #07101f;
  --accent-soft: rgba(108, 140, 255, 0.14);

  --good: #3ddc97;
  --bad: #ff6b7a;
  --warn: #f0b429;

  --band-beginner: #3ddc97;
  --band-intermediate: #6c8cff;
  --band-advanced: #f0b429;
  --band-expert: #ff6b7a;

  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-2: 0 6px 20px -8px rgba(0, 0, 0, 0.55);
  --shadow-3: 0 18px 40px -16px rgba(0, 0, 0, 0.65);
  --ring: 0 0 0 3px var(--accent-soft);

  --r-sm: 8px;
  --r: 14px;
  --r-lg: 20px;
  --r-pill: 999px;

  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.5rem;
  --sp-6: 2rem;
  --sp-7: 3rem;

  --max-width: 68rem;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

[data-theme='light'] {
  color-scheme: light;

  --bg: #f4f6fb;
  --bg-glow: #e4eaff;
  --surface: #ffffff;
  --surface-2: #f7f9fc;
  --surface-3: #eef2f8;
  --border: #dde3ed;
  --border-strong: #c4cdde;

  --text: #121722;
  --text-muted: #49536a;
  --text-faint: #566075;

  --accent: #3a5de0;
  --accent-2: #0fae98;
  --accent-ink: #ffffff;
  --accent-soft: rgba(58, 93, 224, 0.12);

  --good: #0f9d63;
  --bad: #d93a4c;
  --warn: #b57c08;

  --band-beginner: #0f9d63;
  --band-intermediate: #3a5de0;
  --band-advanced: #b57c08;
  --band-expert: #d93a4c;

  --shadow-1: 0 1px 2px rgba(16, 24, 40, 0.06);
  --shadow-2: 0 8px 22px -10px rgba(16, 24, 40, 0.18);
  --shadow-3: 0 20px 44px -20px rgba(16, 24, 40, 0.28);
}

/* ============================================================== 2. Base */

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(1100px 520px at 50% -10%, var(--bg-glow), transparent 60%),
    var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  font-size: clamp(0.95rem, 0.9rem + 0.2vw, 1.05rem);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 var(--sp-2); font-weight: 650; letter-spacing: -0.015em; }
h1 { font-size: clamp(1.6rem, 1.3rem + 1.4vw, 2.3rem); }
h2 { font-size: clamp(1.2rem, 1.05rem + 0.6vw, 1.5rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 var(--sp-3); }
.muted { color: var(--text-muted); }
.small { font-size: 0.85rem; }

main {
  flex: 1;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--sp-6) var(--sp-5) var(--sp-7);
}
main:focus { outline: none; }

/* Views fade in so navigation feels like movement, not a repaint. */
main > section { animation: rise 0.28s var(--ease) both; }
@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--accent); color: var(--accent-ink);
  padding: var(--sp-3) var(--sp-4); border-radius: 0 0 var(--r-sm) 0;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

/* ============================================================== 3. Chrome */

.app-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.app-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--sp-3) var(--sp-5);
  display: flex; align-items: center; justify-content: space-between; gap: var(--sp-4);
}

.brand {
  background: none; border: none; color: var(--text);
  font-size: 1.05rem; font-weight: 700; letter-spacing: -0.02em;
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2); cursor: pointer;
}

.nav-actions { display: flex; align-items: center; gap: var(--sp-1); }
.nav-actions button {
  background: none; border: none; color: var(--text-muted);
  padding: var(--sp-2) var(--sp-3); border-radius: var(--r-pill);
  font: inherit; font-size: 0.92rem; cursor: pointer;
  transition: color 0.15s var(--ease), background 0.15s var(--ease);
}
.nav-actions button:hover { color: var(--text); background: var(--surface-2); }

.app-footer {
  border-top: 1px solid var(--border);
  padding: var(--sp-5);
  text-align: center;
  color: var(--text-faint);
  font-size: 0.85rem;
}
.app-footer p { max-width: 48rem; margin: 0 auto var(--sp-2); }

.link-button {
  background: none; border: none; color: var(--text-muted);
  text-decoration: underline; text-underline-offset: 3px;
  padding: var(--sp-1); font: inherit; cursor: pointer;
}
.link-button:hover { color: var(--bad); }

.notice {
  max-width: var(--max-width);
  margin: var(--sp-4) auto 0;
  padding: var(--sp-3) var(--sp-4);
  border: 1px solid var(--warn);
  border-left-width: 4px;
  border-radius: var(--r-sm);
  background: color-mix(in srgb, var(--warn) 12%, transparent);
}

/* ============================================================== 4. Buttons */

button { font: inherit; }

button.primary {
  background: linear-gradient(135deg, var(--accent), color-mix(in srgb, var(--accent) 70%, var(--accent-2)));
  color: var(--accent-ink);
  border: none;
  padding: var(--sp-3) var(--sp-5);
  border-radius: var(--r-sm);
  font-weight: 650;
  cursor: pointer;
  box-shadow: var(--shadow-1);
  transition: transform 0.12s var(--ease), box-shadow 0.18s var(--ease), filter 0.15s var(--ease);
}
button.primary:hover:not(:disabled) { transform: translateY(-1px); box-shadow: var(--shadow-2); filter: brightness(1.05); }
button.primary:active:not(:disabled) { transform: translateY(0); }
button.primary:disabled { opacity: 0.45; cursor: not-allowed; }

button.ghost {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: border-color 0.15s var(--ease), background 0.15s var(--ease), transform 0.12s var(--ease);
}
button.ghost:hover:not(:disabled) { border-color: var(--border-strong); background: var(--surface-3); transform: translateY(-1px); }
button.ghost.small { padding: var(--sp-1) var(--sp-3); font-size: 0.85rem; border-radius: var(--r-pill); }
button.ghost:disabled { opacity: 0.45; cursor: not-allowed; }

button.back {
  background: none; border: none; color: var(--text-muted);
  padding: var(--sp-2) 0; margin-bottom: var(--sp-3);
  display: inline-flex; align-items: center; gap: var(--sp-2);
}
button.back:hover { color: var(--text); }

select {
  background: var(--surface-2); color: var(--text);
  border: 1px solid var(--border); border-radius: var(--r-sm);
  padding: var(--sp-2) var(--sp-3); font: inherit; cursor: pointer;
}
select:hover { border-color: var(--border-strong); }

.row-actions { display: flex; flex-wrap: wrap; gap: var(--sp-3); align-items: center; margin-top: var(--sp-5); }
.section-label {
  font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--text-faint);
  margin: var(--sp-6) 0 var(--sp-3);
}

/* ============================================================== 5. Cards */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: var(--sp-4);
  margin-top: var(--sp-4);
}

.card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: var(--sp-5);
  display: flex; flex-direction: column; gap: var(--sp-2);
  box-shadow: var(--shadow-1);
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), border-color 0.18s var(--ease);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-3); border-color: var(--border-strong); }
.card h2, .card h3 { margin: 0; }
.card p { margin: 0; }
.card > button { margin-top: auto; }

/* The accent hairline only appears on hover, so the grid stays calm at rest. */
.card::before {
  content: '';
  position: absolute; inset: 0 0 auto;
  height: 2px; border-radius: var(--r) var(--r) 0 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  opacity: 0; transition: opacity 0.2s var(--ease);
}
.card:hover::before { opacity: 1; }

.category-card { align-items: flex-start; }
.category-icon {
  font-size: 1.5rem; line-height: 1;
  width: 2.75rem; height: 2.75rem;
  display: grid; place-items: center;
  border-radius: var(--r-sm);
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: var(--sp-1);
}

.remaining { font-weight: 600; font-size: 0.9rem; color: var(--text-muted); }
.mode-label { font-size: 0.85rem; color: var(--text-faint); }

/* Thin progress rail under category and trainer cards. */
.meter { height: 5px; border-radius: var(--r-pill); background: var(--surface-3); overflow: hidden; }
.meter-fill {
  display: block; height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: inherit;
  transition: width 0.4s var(--ease);
}
.meter-done .meter-fill { background: var(--good); }

.variant-card { gap: var(--sp-1); }
.variant-card h3 { font-size: 1.25rem; }
.variant-done { opacity: 0.6; }
.variant-done:hover { transform: none; box-shadow: var(--shadow-1); }
.done-label { color: var(--good); font-weight: 650; font-size: 0.9rem; margin-top: auto; }

/* Difficulty is carried by a label as well as a colour (FR-161). */
.band-stripe {
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 4px; border-radius: var(--r) 0 0 var(--r);
}
.band-beginner { background: var(--band-beginner); }
.band-intermediate { background: var(--band-intermediate); }
.band-advanced { background: var(--band-advanced); }
.band-expert { background: var(--band-expert); }

.badge {
  display: inline-flex; align-items: center; gap: var(--sp-1);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--r-pill);
  background: var(--surface-3);
  border: 1px solid var(--border);
  font-size: 0.8rem; font-weight: 600;
  white-space: nowrap;
}
.badge-done { color: var(--text-faint); }
.badge-practice { background: var(--accent-soft); border-color: transparent; color: var(--accent); }

.hero {
  display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: var(--sp-4); margin-bottom: var(--sp-5);
}
.hero-text { max-width: 36rem; }
.hero-meter { min-width: 14rem; flex: 0 1 18rem; }
.hero-meter .meter { height: 8px; }
.hero-count { font-size: 0.85rem; color: var(--text-muted); margin-bottom: var(--sp-2); }

/* ============================================================== 6. Stats */

.stat { display: flex; flex-direction: column; gap: 2px; min-width: 4.5rem; }
.stat-label {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--text-faint); font-weight: 650;
}
.stat-value { font-size: 1.3rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.stat-value.stat-headline {
  font-size: clamp(2.4rem, 2rem + 2vw, 3.4rem);
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.stat-time .stat-value, .stat-lives .stat-value, .stat-pairs .stat-value { color: var(--text); }
.timer-low .stat-value, .stat-time.timer-low .stat-value { color: var(--bad); }

.result-stats, .brief-stats {
  display: flex; flex-wrap: wrap; gap: var(--sp-5);
  padding: var(--sp-4) var(--sp-5);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  margin: var(--sp-4) 0;
}

/* ============================================================== 7. Round */

.round-header {
  position: sticky; top: 3.4rem; z-index: 20;
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-3) var(--sp-4);
  margin-bottom: var(--sp-5);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--shadow-2);
}
.round-status { display: flex; flex-wrap: wrap; gap: var(--sp-5); }
.round-meta { display: flex; align-items: center; gap: var(--sp-2); }

.timer-rail { height: 4px; border-radius: var(--r-pill); background: var(--surface-3); overflow: hidden; margin-bottom: var(--sp-4); }
.timer-bar { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: inherit; }
.timer-bar.low { background: var(--bad); }

.round-body { min-height: 16rem; display: flex; flex-direction: column; align-items: center; text-align: center; }
.round-body > * { width: 100%; max-width: 34rem; }

.question {
  font-size: clamp(1.5rem, 1.1rem + 2.2vw, 2.4rem);
  font-weight: 650; letter-spacing: -0.02em;
  margin: var(--sp-4) 0 var(--sp-3);
  font-variant-numeric: tabular-nums;
}
.format-hint { color: var(--text-muted); font-size: 0.88rem; margin-bottom: var(--sp-3); }
.level-label { font-size: 1.1rem; font-weight: 650; color: var(--text-muted); margin-top: var(--sp-3); }
.guess-counter { color: var(--warn); font-weight: 600; }

.answer-row { display: flex; gap: var(--sp-3); flex-wrap: wrap; justify-content: center; }
.answer-input {
  flex: 1 1 14rem;
  font: inherit; font-size: 1.15rem;
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
  text-align: center;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.answer-input:focus { outline: none; border-color: var(--accent); box-shadow: var(--ring); }
.answer-input::placeholder { color: var(--text-faint); }

.choices {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: var(--sp-3);
  margin-top: var(--sp-4);
}
.choice {
  display: flex; align-items: center; gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer; text-align: left; font-size: 1rem;
  transition: border-color 0.15s var(--ease), background 0.15s var(--ease), transform 0.12s var(--ease);
}
.choice:hover { border-color: var(--accent); background: var(--surface-2); transform: translateY(-2px); }
.choice kbd {
  flex: none;
  min-width: 1.5rem; height: 1.5rem;
  display: grid; place-items: center;
  background: var(--surface-3); border-radius: var(--r-sm);
  font-size: 0.75rem; font-family: inherit; color: var(--text-muted);
}

.round-feedback { min-height: 3rem; margin-top: var(--sp-4); display: flex; flex-direction: column; align-items: center; gap: var(--sp-1); }
.feedback {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--r-pill);
  font-weight: 650;
  animation: pop 0.22s var(--ease) both;
  margin: 0;
}
.feedback-correct { background: color-mix(in srgb, var(--good) 16%, transparent); color: var(--good); }
.feedback-wrong { background: color-mix(in srgb, var(--bad) 14%, transparent); color: var(--bad); }
.feedback-life { color: var(--bad); font-size: 0.85rem; margin: 0; }
@keyframes pop {
  from { opacity: 0; transform: scale(0.94); }
  to { opacity: 1; transform: scale(1); }
}

.flag-display { font-size: clamp(4rem, 3rem + 10vw, 7rem); line-height: 1.1; }
.outline-display { display: flex; justify-content: center; padding: var(--sp-3) 0; }
.outline-svg {
  width: min(280px, 64vw); height: auto;
  fill: var(--accent);
  filter: drop-shadow(0 6px 16px color-mix(in srgb, var(--accent) 35%, transparent));
}

.hints { list-style: none; padding: 0; margin: var(--sp-4) 0 0; display: flex; flex-direction: column; gap: var(--sp-2); }
.hint {
  display: grid; grid-template-columns: 1fr auto auto auto;
  gap: var(--sp-4); align-items: center;
  padding: var(--sp-2) var(--sp-4);
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-sm);
  animation: rise 0.2s var(--ease) both;
  text-align: left;
}
.hint-guess { font-weight: 600; }
.hint-distance { color: var(--text-muted); font-variant-numeric: tabular-nums; }
.hint-arrow { font-size: 1.15rem; color: var(--accent); }
.hint-proximity { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--accent-2); }

/* ------------------------------------------------- Pattern Memory board */

.tile-grid { display: grid; gap: var(--sp-2); max-width: 24rem; margin: var(--sp-4) auto; width: 100%; }
.tile {
  aspect-ratio: 1;
  border-radius: var(--r-sm);
  border: 1px solid var(--border);
  background: var(--surface-2);
  cursor: pointer;
  display: grid; place-items: center;
  font-size: 1.4rem; color: var(--accent);
  transition: background 0.14s var(--ease), border-color 0.14s var(--ease), transform 0.12s var(--ease);
}
.tile:hover:not(:disabled) { border-color: var(--border-strong); transform: scale(1.04); }
.tile:disabled { cursor: default; }
.tile-lit {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  box-shadow: 0 0 20px -2px color-mix(in srgb, var(--accent) 60%, transparent);
  animation: pop 0.2s var(--ease) both;
}
.tile-selected { border-color: var(--accent); background: var(--accent-soft); }
.tile-selected::after { content: '✓'; font-weight: 700; }

/* ------------------------------------------------- Figure Pairs board */

.pair-board { display: grid; gap: var(--sp-2); max-width: 28rem; margin: var(--sp-4) auto; width: 100%; }
.pair-card {
  aspect-ratio: 1;
  border-radius: var(--r-sm);
  border: 1px solid var(--border);
  background: var(--surface-2);
  cursor: pointer;
  display: grid; place-items: center;
  font-size: clamp(1.2rem, 4.5vw, 2rem);
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease), transform 0.16s var(--ease);
}
.pair-card:hover:not(:disabled) { border-color: var(--border-strong); transform: translateY(-2px); }
.pair-card-face-up {
  background: var(--surface-3);
  border-color: var(--accent);
  animation: flip 0.24s var(--ease) both;
}
.pair-card-matched {
  background: color-mix(in srgb, var(--good) 14%, transparent);
  border-color: color-mix(in srgb, var(--good) 45%, transparent);
  cursor: default; opacity: 0.75;
}
@keyframes flip {
  from { transform: rotateY(70deg); opacity: 0.4; }
  to { transform: rotateY(0); opacity: 1; }
}

/* ============================================================== 8. Results */

.results { text-align: center; }
.results .result-stats { justify-content: center; text-align: left; }
.end-reason {
  display: inline-block;
  padding: var(--sp-1) var(--sp-4);
  border-radius: var(--r-pill);
  background: var(--surface-3);
  font-weight: 600; font-size: 0.9rem;
}
.comparison { display: flex; flex-direction: column; gap: var(--sp-2); margin: var(--sp-5) auto; max-width: 34rem; }
.compare {
  margin: 0;
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  background: var(--surface);
  border: 1px solid var(--border);
  border-left-width: 4px;
  text-align: left;
}
.compare-better, .compare-new-best, .compare-first {
  border-left-color: var(--good);
  background: color-mix(in srgb, var(--good) 8%, var(--surface));
}
.compare-worse, .compare-below { border-left-color: var(--bad); }
.compare-equal { border-left-color: var(--warn); }
.weak-area {
  margin: var(--sp-4) auto 0; max-width: 34rem;
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  background: var(--surface); border: 1px solid var(--border);
}
.practice-note { font-style: italic; color: var(--text-muted); }
.results .row-actions { justify-content: center; }

/* ============================================================== 9. Briefing */

.briefing { max-width: 42rem; }
.brief-mode { font-size: 1.2rem; font-weight: 650; }
.warning {
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-sm);
  background: color-mix(in srgb, var(--warn) 12%, transparent);
  border-left: 4px solid var(--warn);
}

/* ============================================================== 10. Practice */

.filter {
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: var(--sp-4) var(--sp-5);
  margin: var(--sp-4) 0;
  background: var(--surface);
}
.filter legend { padding: 0 var(--sp-2); font-weight: 650; font-size: 0.9rem; }
.filter-options { display: flex; flex-wrap: wrap; gap: var(--sp-2); }
.filter-option {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--surface-2);
  cursor: pointer; font-size: 0.9rem;
  transition: border-color 0.15s var(--ease), background 0.15s var(--ease);
}
.filter-option:hover { border-color: var(--border-strong); }
.filter-option:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}
.filter-option input { accent-color: var(--accent); margin: 0; }

/* ============================================================== 11. Archive */

.archive-list { display: flex; flex-direction: column; gap: var(--sp-2); margin-top: var(--sp-4); }
.archive-day {
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--surface);
  overflow: hidden;
}
.archive-day summary {
  display: flex; justify-content: space-between; align-items: center;
  gap: var(--sp-4); padding: var(--sp-3) var(--sp-4);
  cursor: pointer; font-weight: 600;
  list-style: none;
}
.archive-day summary::-webkit-details-marker { display: none; }
.archive-day summary:hover { background: var(--surface-2); }
.archive-day[open] summary { border-bottom: 1px solid var(--border); }
.archive-trainers { display: flex; flex-direction: column; gap: var(--sp-4); padding: var(--sp-4); }
.card { font-size: 1rem; }
.card h2 { font-size: 1.15rem; }
.archive-trainer h2 { margin: 0 0 var(--sp-2); font-size: 0.9rem; color: var(--text-muted); font-weight: 650; }
.archive-variants { display: flex; flex-wrap: wrap; gap: var(--sp-2); }

/* ============================================================== 12. Progress */

.chart-wrap {
  overflow-x: auto;
  margin: var(--sp-2) 0 var(--sp-5);
  padding: var(--sp-4);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
}
.chart { width: 100%; min-width: 20rem; height: auto; }
.chart-grid { stroke: var(--border); stroke-width: 1; }
.chart-line { fill: none; stroke: var(--accent); stroke-width: 2.5; stroke-linejoin: round; stroke-linecap: round; }
.chart-point { fill: var(--accent); stroke: var(--surface); stroke-width: 2; }
.chart-axis { fill: var(--text-faint); font-size: 11px; }

.topic-breakdown { margin-top: var(--sp-6); }
.topic-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: var(--sp-3); }
.topic-row { display: grid; grid-template-columns: minmax(8rem, 1fr) 2fr auto; gap: var(--sp-4); align-items: center; }
.topic-name { font-weight: 600; font-size: 0.9rem; }
.topic-bar { background: var(--surface-3); border-radius: var(--r-pill); height: 8px; overflow: hidden; }
.topic-fill { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--accent), var(--accent-2)); }
.topic-value { font-variant-numeric: tabular-nums; font-size: 0.82rem; color: var(--text-muted); }

.empty-state {
  padding: var(--sp-7) var(--sp-5);
  text-align: center;
  color: var(--text-muted);
  border: 1px dashed var(--border);
  border-radius: var(--r);
  background: var(--surface);
}

/* ============================================================== 13. Small screens */

@media (max-width: 640px) {
  main { padding: var(--sp-4) var(--sp-4) var(--sp-6); }
  .app-nav { padding: var(--sp-2) var(--sp-3); flex-wrap: wrap; row-gap: var(--sp-1); }
  .brand { font-size: 0.95rem; padding: var(--sp-1); }
  .nav-actions { flex-wrap: wrap; justify-content: flex-end; }
  .nav-actions button { padding: var(--sp-1) var(--sp-2); font-size: 0.82rem; }
  .round-header { position: static; gap: var(--sp-3); padding: var(--sp-3); }
  .round-status { gap: var(--sp-4); width: 100%; justify-content: space-between; }
  .stat-value { font-size: 1.1rem; }
  .result-stats, .brief-stats { gap: var(--sp-4); padding: var(--sp-4); }
  .topic-row { grid-template-columns: 1fr; gap: var(--sp-1); }
  .hint { grid-template-columns: 1fr auto; gap: var(--sp-2) var(--sp-3); }
  .choices { grid-template-columns: 1fr; }
  .hero { flex-direction: column; align-items: stretch; }
}

/* People trainer: a clue is a sentence, not a sum. */
.prompt-prefix {
  font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--text-faint); margin: var(--sp-4) 0 0;
}
.question-long {
  font-size: clamp(1.05rem, 0.95rem + 0.7vw, 1.35rem);
  font-weight: 500;
  line-height: 1.45;
  letter-spacing: 0;
  max-width: 32rem;
  margin-inline: auto;
}

/* Famous People portraits */
.portrait { margin: 0 auto var(--sp-3); display: flex; flex-direction: column; align-items: center; gap: var(--sp-2); }
.portrait-image {
  width: clamp(130px, 34vw, 190px);
  aspect-ratio: 1;
  object-fit: cover;
  object-position: 50% 22%;
  border-radius: var(--r);
  border: 1px solid var(--border);
  background: var(--surface-2);
  box-shadow: var(--shadow-2);
}
.portrait-credit { font-size: 0.7rem; color: var(--text-faint); max-width: 22rem; }

.topic-chip { margin: 0 0 var(--sp-2); }