/* Life in the Universe: study app styles. Dark "space" theme by default. */

:root {
  color-scheme: dark;
  --bg: #070b18;
  --bg-glow-1: rgba(244, 183, 64, 0.10);
  --bg-glow-2: rgba(92, 112, 255, 0.14);
  --surface: #0f1730;
  --surface-2: #16203f;
  --surface-3: #1d2950;
  --line: #27345a;
  --line-strong: #3a4a78;
  --text: #e9edf7;
  --text-soft: #c4cce0;
  --muted: #98a3c0;
  --accent: #f4b740;
  --accent-hover: #ffc95e;
  --accent-ink: #1b1204;
  --accent-text: #f7c25a;
  --accent-soft: rgba(244, 183, 64, 0.13);
  --good: #5ee08f;
  --good-soft: rgba(94, 224, 143, 0.12);
  --bad: #ff7a8f;
  --bad-soft: rgba(255, 122, 143, 0.12);
  --bad-strong: #e5485f;
  --focus: #ffd47e;
  --star: rgba(255, 255, 255, 0.9);
  --star-dim: rgba(196, 210, 255, 0.55);
  --stars-opacity: 1;
  --nav-bg: rgba(7, 11, 24, 0.86);
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.45);

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", Arial, sans-serif;
  --font-display: ui-serif, "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --gutter: 16px;
  --radius: 14px;
  --radius-sm: 10px;
  --tap: 44px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    color-scheme: light;
    --bg: #f4f1e8;
    --bg-glow-1: rgba(214, 140, 20, 0.12);
    --bg-glow-2: rgba(70, 90, 200, 0.08);
    --surface: #fffdf8;
    --surface-2: #f0ece0;
    --surface-3: #e7e1d1;
    --line: #d8d1bf;
    --line-strong: #b9b09a;
    --text: #141a2e;
    --text-soft: #2b3350;
    --muted: #535c74;
    --accent: #f0b232;
    --accent-hover: #f7c04d;
    --accent-ink: #1b1204;
    --accent-text: #8a4f00;
    --accent-soft: rgba(214, 140, 20, 0.14);
    --good: #157a3c;
    --good-soft: rgba(21, 122, 60, 0.10);
    --bad: #b4123a;
    --bad-soft: rgba(180, 18, 58, 0.08);
    --bad-strong: #b4123a;
    --focus: #1f4fd6;
    --star: rgba(20, 26, 46, 0.55);
    --star-dim: rgba(20, 26, 46, 0.3);
    --stars-opacity: 0.35;
    --nav-bg: rgba(244, 241, 232, 0.9);
    --shadow: 0 18px 50px rgba(40, 32, 10, 0.18);
  }
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f4f1e8;
  --bg-glow-1: rgba(214, 140, 20, 0.12);
  --bg-glow-2: rgba(70, 90, 200, 0.08);
  --surface: #fffdf8;
  --surface-2: #f0ece0;
  --surface-3: #e7e1d1;
  --line: #d8d1bf;
  --line-strong: #b9b09a;
  --text: #141a2e;
  --text-soft: #2b3350;
  --muted: #535c74;
  --accent: #f0b232;
  --accent-hover: #f7c04d;
  --accent-ink: #1b1204;
  --accent-text: #8a4f00;
  --accent-soft: rgba(214, 140, 20, 0.14);
  --good: #157a3c;
  --good-soft: rgba(21, 122, 60, 0.10);
  --bad: #b4123a;
  --bad-soft: rgba(180, 18, 58, 0.08);
  --bad-strong: #b4123a;
  --focus: #1f4fd6;
  --star: rgba(20, 26, 46, 0.55);
  --star-dim: rgba(20, 26, 46, 0.3);
  --stars-opacity: 0.35;
  --nav-bg: rgba(244, 241, 232, 0.9);
  --shadow: 0 18px 50px rgba(40, 32, 10, 0.18);
}

/* ---------- base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.55;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
button, input { font: inherit; color: inherit; }
h1, h2, h3 { line-height: 1.2; margin: 0; }
p { margin: 0; }
ol, ul { margin: 0; padding: 0; list-style: none; }
[hidden] { display: none !important; }

:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 6px; }
main:focus, [data-autofocus]:focus, h1[tabindex="-1"]:focus { outline: none; }

.sr-only {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: var(--gutter); top: -100px; z-index: 50;
  background: var(--accent); color: var(--accent-ink);
  padding: 10px 16px; border-radius: var(--radius-sm); font-weight: 700; text-decoration: none;
}
.skip-link:focus { top: 10px; }

.muted { color: var(--muted); }
.small { font-size: 0.875rem; }

/* ---------- starfield ---------- */
.sky {
  position: fixed; inset: 0; z-index: -1; pointer-events: none; overflow: hidden;
  background-image:
    radial-gradient(60rem 40rem at 110% -10%, var(--bg-glow-1), transparent 60%),
    radial-gradient(50rem 40rem at -20% 110%, var(--bg-glow-2), transparent 60%);
}
.stars { opacity: var(--stars-opacity); }
.sky .stars { position: absolute; inset: -50% -10% -10% -10%; background-repeat: repeat; }
.stars-1 {
  background-image:
    radial-gradient(1px 1px at 23px 41px, var(--star-dim) 99%, transparent),
    radial-gradient(1px 1px at 97px 13px, var(--star-dim) 99%, transparent),
    radial-gradient(1px 1px at 151px 121px, var(--star-dim) 99%, transparent),
    radial-gradient(1px 1px at 61px 173px, var(--star-dim) 99%, transparent),
    radial-gradient(1px 1px at 193px 67px, var(--star-dim) 99%, transparent),
    radial-gradient(1px 1px at 131px 199px, var(--star-dim) 99%, transparent);
  background-size: 220px 220px;
}
.stars-2 {
  background-image:
    radial-gradient(1.4px 1.4px at 47px 83px, var(--star) 99%, transparent),
    radial-gradient(1.4px 1.4px at 263px 29px, var(--star) 99%, transparent),
    radial-gradient(1.4px 1.4px at 181px 251px, var(--star) 99%, transparent),
    radial-gradient(1.4px 1.4px at 311px 173px, var(--star) 99%, transparent);
  background-size: 360px 360px;
  animation: twinkle 7s ease-in-out infinite alternate;
}
.stars-3 {
  background-image:
    radial-gradient(2px 2px at 113px 157px, var(--star) 99%, transparent),
    radial-gradient(1.6px 1.6px at 421px 61px, var(--star) 99%, transparent),
    radial-gradient(2px 2px at 337px 389px, var(--star) 99%, transparent);
  background-size: 520px 520px;
  animation: drift 120s linear infinite;
}
@keyframes twinkle { from { opacity: calc(0.45 * var(--stars-opacity)); } to { opacity: var(--stars-opacity); } }
@keyframes drift { from { transform: translateY(0); } to { transform: translateY(520px); } }

/* ---------- shell ---------- */
.topbar-inner, .view, .footer-inner {
  width: 100%;
  max-width: 980px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 64px; }
.brand {
  display: inline-flex; align-items: center; gap: 10px; min-height: var(--tap);
  text-decoration: none; font-family: var(--font-display); font-size: 1.05rem; letter-spacing: 0.01em;
}
.brand-mark {
  position: relative; width: 22px; height: 22px; border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, var(--accent-hover), var(--accent) 45%, #b9781a 100%);
  box-shadow: 0 0 0 4px var(--bg), 0 0 0 5px var(--line-strong);
}
.brand-mark::after {
  content: ""; position: absolute; width: 5px; height: 5px; border-radius: 50%;
  background: var(--text); top: -6px; right: -5px;
}
.theme-toggle {
  display: inline-flex; align-items: center; gap: 8px; min-height: var(--tap); min-width: var(--tap);
  padding: 0 12px; border-radius: 999px; border: 1px solid var(--line);
  background: transparent; cursor: pointer; font-family: var(--font-mono); font-size: 0.75rem;
  text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted);
}
.theme-toggle:hover { border-color: var(--line-strong); color: var(--text); }
.theme-icon {
  width: 16px; height: 16px; border-radius: 50%; border: 2px solid currentColor;
  background: linear-gradient(90deg, currentColor 50%, transparent 50%);
}
.theme-toggle[data-mode="dark"] .theme-icon { background: currentColor; }
.theme-toggle[data-mode="light"] .theme-icon { background: transparent; }

main.view { flex: 1; padding-block: 8px 48px; }
.loading { padding: 48px 0; color: var(--muted); }

.site-footer { border-top: 1px solid var(--line); }
.footer-inner {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 4px 20px;
  padding-block: 8px; font-size: 0.875rem; color: var(--muted);
}
.footer-inner nav { display: flex; gap: 4px 18px; flex-wrap: wrap; }
.footer-inner a { display: inline-flex; align-items: center; min-height: var(--tap); text-underline-offset: 3px; color: var(--text-soft); }
.footer-inner a:hover { color: var(--accent-text); }
.footer-note { padding-block: 10px; }

/* ---------- type ---------- */
.eyebrow {
  font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--accent-text); margin-bottom: 10px;
}
.display, .page-head h1, .score-copy h1, .empty h1 {
  font-family: var(--font-display); font-weight: 600; letter-spacing: -0.01em;
}
.display { font-size: clamp(2.4rem, 9vw, 4.2rem); line-height: 1.02; }
.page-head h1, .empty h1 { font-size: clamp(2rem, 7vw, 3rem); }
.lede { color: var(--text-soft); font-size: 1.05rem; max-width: 38rem; margin-top: 12px; }
h2 { font-size: 0.8rem; font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.14em; color: var(--muted); font-weight: 600; }
.lecture-id {
  font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.06em; color: var(--accent-text);
  border: 1px solid var(--line); border-radius: 6px; padding: 1px 6px; white-space: nowrap;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  min-height: var(--tap); padding: 0 18px; border-radius: 12px;
  border: 1px solid transparent; background: transparent; color: var(--text);
  font-weight: 650; font-size: 0.975rem; text-decoration: none; cursor: pointer;
  transition: background-color 0.15s, border-color 0.15s, color 0.15s, transform 0.15s var(--ease);
  -webkit-tap-highlight-color: transparent;
}
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); }
.btn-outline { border-color: var(--line-strong); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent-text); }
.btn-ghost { color: var(--text-soft); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); color: var(--text); }
.btn-danger { background: var(--bad-strong); color: #fff; }
.btn-danger:hover { filter: brightness(1.08); }
.btn-quiet-danger { color: var(--bad); border: 1px dashed var(--line-strong); }
.btn-quiet-danger:hover { border-color: var(--bad); background: var(--bad-soft); }
.btn-small { padding: 0 14px; border: 1px solid var(--line-strong); font-size: 0.9rem; }
.btn-small:hover { border-color: var(--accent); color: var(--accent-text); }
.btn-wide { width: 100%; }
.back {
  white-space: nowrap;
  display: inline-flex; align-items: center; min-height: var(--tap); margin-left: -4px; padding-inline: 4px;
  color: var(--muted); text-decoration: none; font-size: 0.9rem;
}
.back:hover { color: var(--text); }

/* ---------- rings ---------- */
.ring-track { stroke: var(--line); }
.ring-fill { stroke: var(--accent); transition: stroke-dasharray 0.8s var(--ease); }
.ring-empty .ring-fill { stroke: transparent; }

/* ---------- home ---------- */
.hero {
  position: relative; display: grid; gap: 28px; padding-block: 28px 32px;
  border-bottom: 1px solid var(--line);
}
.hero-stat { position: relative; display: flex; align-items: center; gap: 18px; }
.hero-stat .ring-xl { flex: none; }
.hero-stat-text { display: flex; flex-direction: column; }
.big-num { font-family: var(--font-display); font-size: 2.4rem; line-height: 1; }
.orbit {
  position: absolute; left: 56px; top: 56px; width: 240px; height: 240px; margin: -120px 0 0 -120px;
  border-radius: 50%; border: 1px solid var(--line-strong); pointer-events: none;
  transform: rotate(-20deg) scaleY(0.34);
  opacity: 0.8;
}
.orbit::before {
  content: ""; position: absolute; inset: -38px; border-radius: 50%; border: 1px dashed var(--line);
}
.orbit-body {
  position: absolute; inset: 0; border-radius: 50%;
  animation: orbit 18s linear infinite;
}
.orbit-body::after {
  content: ""; position: absolute; top: -6px; left: calc(50% - 6px); width: 12px; height: 12px;
  border-radius: 50%; background: var(--text); box-shadow: 0 0 12px var(--accent);
}
@keyframes orbit { to { transform: rotate(360deg); } }
.ring-xl, .hero-stat-text { position: relative; }

.resume {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px;
  margin-top: 24px; padding: 16px; border-radius: var(--radius);
  background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 45%, transparent);
}
.resume-title { font-weight: 700; }
.resume-actions { display: flex; gap: 8px; }

.actions { margin-top: 12px; }
.action {
  position: relative; display: grid; grid-template-columns: 1fr auto; column-gap: 16px;
  padding: 20px 4px; border-bottom: 1px solid var(--line); text-decoration: none;
  transition: padding 0.2s var(--ease), background-color 0.2s;
}
.action > span:not(.action-arrow) { grid-column: 1; }
.action-kicker { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.action-title { font-family: var(--font-display); font-size: clamp(1.6rem, 6vw, 2.2rem); line-height: 1.15; margin-top: 2px; }
.action-desc { color: var(--text-soft); margin-top: 4px; }
.action-arrow {
  grid-column: 2; grid-row: 1 / span 3; align-self: center;
  display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%;
  border: 1px solid var(--line-strong); font-size: 1.2rem;
  transition: background-color 0.2s, color 0.2s, border-color 0.2s, transform 0.2s var(--ease);
}
.action:hover .action-arrow, .action:focus-visible .action-arrow { transform: translateX(4px); border-color: var(--accent); }
.action-primary .action-title { color: var(--accent-text); }
.action-primary .action-arrow { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.action:focus-visible { outline-offset: 0; }

.section-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 6px 16px; margin-bottom: 8px; }
.lectures, .recent, .breakdown, .review { margin-top: 44px; }
.lecture-row {
  display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 14px;
  padding: 14px 0; border-bottom: 1px solid var(--line);
}
.lecture-row:first-child { border-top: 1px solid var(--line); }
.lecture-info { display: flex; flex-direction: column; align-items: flex-start; gap: 3px; min-width: 0; }
.lecture-name { font-weight: 650; font-size: 1.02rem; }

.recent-list { border-top: 1px solid var(--line); }
.recent-row {
  display: grid; grid-template-columns: 4.5rem 1fr auto; gap: 12px; align-items: center;
  padding: 12px 0; border-bottom: 1px solid var(--line); font-size: 0.95rem;
}
.recent-date { font-family: var(--font-mono); font-size: 0.8rem; color: var(--muted); }
.recent-score { font-family: var(--font-mono); font-weight: 700; }
.reset { margin-top: 44px; }

/* ---------- setup ---------- */
.page-head { padding-block: 12px 24px; }
.setup-form { display: grid; gap: 26px; }
.field { border: 0; margin: 0; padding: 0; min-width: 0; }
.field legend { padding: 0; margin-bottom: 10px; font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.choice { position: relative; }
.choice input { position: absolute; opacity: 0; width: 1px; height: 1px; margin: 0; }
.choice label { cursor: pointer; -webkit-tap-highlight-color: transparent; }
.choice input:focus-visible + label { outline: 3px solid var(--focus); outline-offset: 2px; }
.choice input:disabled + label { opacity: 0.35; cursor: not-allowed; }

.segmented { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.segmented-2 { grid-template-columns: repeat(2, 1fr); }
.segmented-5 { grid-template-columns: repeat(5, 1fr); }
.segmented label {
  display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center;
  min-height: 56px; padding: 8px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--surface); transition: border-color 0.15s, background-color 0.15s;
}
.segmented .choice-label { font-family: var(--font-mono); font-size: 1.15rem; font-weight: 700; }
.segmented-2 .choice-label { font-family: var(--font-sans); font-size: 1rem; }
.segmented .choice-hint { font-size: 0.78rem; color: var(--muted); }
.segmented label:hover { border-color: var(--line-strong); }
.segmented input:checked + label { border-color: var(--accent); background: var(--accent-soft); box-shadow: inset 0 0 0 1px var(--accent); }
.segmented input:checked + label .choice-label { color: var(--accent-text); }

.checklist { display: grid; gap: 8px; }
.checklist label {
  display: grid; grid-template-columns: 24px 1fr auto; align-items: center; gap: 12px;
  min-height: 56px; padding: 10px 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface);
}
.checklist label::before {
  content: ""; display: grid; place-items: center; width: 22px; height: 22px; border-radius: 6px;
  border: 2px solid var(--line-strong); color: var(--accent-ink); font-weight: 800; font-size: 14px; line-height: 1;
  transition: background-color 0.15s, border-color 0.15s;
}
.checklist .choice-radio label::before { border-radius: 50%; }
.checklist input:checked + label { border-color: color-mix(in srgb, var(--accent) 60%, var(--line)); }
.checklist .choice-radio input:checked + label::before { border-color: var(--accent); background-color: var(--accent); box-shadow: inset 0 0 0 4px var(--surface); }
.checklist .choice-checkbox input:checked + label::before { content: "\2713"; border-color: var(--accent); background-color: var(--accent); }
.checklist .choice-label { font-weight: 600; min-width: 0; }
.checklist .choice-hint { font-family: var(--font-mono); font-size: 0.78rem; color: var(--muted); white-space: nowrap; }

.setup-footer {
  display: grid; gap: 12px; margin-top: 8px; padding: 18px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--line);
}
.summary { font-size: 1rem; color: var(--text-soft); }
.summary strong { color: var(--text); }
.note { font-size: 0.92rem; color: var(--text-soft); padding: 10px 12px; border-radius: var(--radius-sm); background: var(--surface-2); }
.note-warn { background: var(--accent-soft); color: var(--text); border-left: 3px solid var(--accent); }
.panel { padding: 20px; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--line); }
.weak-start { margin-top: 16px; }
.view-weak .setup-footer { margin-top: 16px; }

/* ---------- quiz ---------- */
.view-quiz { max-width: 760px; }
.quiz { padding-top: 4px; }
.quiz-bar {
  display: grid; grid-template-columns: 1fr auto auto; align-items: center; gap: 12px; min-height: 52px;
}
.quiz-bar-left { display: flex; align-items: center; gap: 12px; min-width: 0; }
.quiz-mode { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.quiz-count { font-family: var(--font-mono); font-size: 0.85rem; color: var(--text-soft); white-space: nowrap; }
.timer {
  font-family: var(--font-mono); font-variant-numeric: tabular-nums; font-weight: 700; font-size: 1rem;
  padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line-strong); min-width: 4.8em; text-align: center;
}
.timer.is-low { color: var(--accent-text); border-color: var(--accent); background: var(--accent-soft); }
.timer.is-critical { color: var(--bad); border-color: var(--bad); background: var(--bad-soft); animation: pulse 1s ease-in-out infinite; }
@keyframes pulse { 50% { opacity: 0.6; } }

.progress { height: 4px; border-radius: 4px; background: var(--line); overflow: hidden; margin-top: 4px; }
.progress-fill { height: 100%; background: var(--accent); transform-origin: left center; transform: scaleX(0); transition: transform 0.35s var(--ease); }

.question-card { padding-block: 28px 8px; }
.q-lecture { margin-bottom: 14px; }
.question-text { font-size: clamp(1.3rem, 5vw, 1.8rem); font-weight: 650; line-height: 1.32; letter-spacing: -0.005em; }
.options { display: grid; gap: 10px; margin-top: 24px; }
.option {
  display: grid; grid-template-columns: 36px 1fr auto; align-items: center; gap: 14px;
  width: 100%; min-height: 60px; padding: 12px 14px; text-align: left;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
  font-size: 1.04rem; line-height: 1.4; cursor: pointer; -webkit-tap-highlight-color: transparent;
  transition: border-color 0.15s, background-color 0.15s, transform 0.15s var(--ease);
}
.option:hover:not([aria-disabled="true"]) { border-color: var(--line-strong); background: var(--surface-2); }
.option:active:not([aria-disabled="true"]) { transform: scale(0.995); }
.option-letter {
  display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%;
  border: 1px solid var(--line-strong); font-family: var(--font-mono); font-weight: 700; font-size: 0.95rem;
  color: var(--text-soft); background: var(--bg);
}
.option-letter-sm { width: 26px; height: 26px; font-size: 0.8rem; flex: none; }
.option-text { min-width: 0; overflow-wrap: anywhere; }
.option-mark { font-weight: 800; font-size: 1.1rem; }
.option.is-chosen { border-color: var(--accent); background: var(--accent-soft); box-shadow: inset 0 0 0 1px var(--accent); }
.option.is-chosen .option-letter { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.option[aria-disabled="true"] { cursor: default; }
.option.is-correct { border-color: var(--good); background: var(--good-soft); box-shadow: inset 0 0 0 1px var(--good); }
.option.is-correct .option-letter { background: var(--good); border-color: var(--good); color: var(--bg); }
.option.is-correct .option-mark { color: var(--good); }
.option.is-wrong { border-color: var(--bad); background: var(--bad-soft); box-shadow: inset 0 0 0 1px var(--bad); }
.option.is-wrong .option-letter { background: var(--bad); border-color: var(--bad); color: var(--bg); }
.option.is-wrong .option-mark { color: var(--bad); }
.option.is-dim { opacity: 0.62; }

.feedback {
  margin-top: 18px; padding: 16px 18px; border-radius: var(--radius); border-left: 4px solid;
  display: grid; gap: 8px; animation: rise 0.25s var(--ease);
}
.feedback-right { border-color: var(--good); background: var(--good-soft); }
.feedback-wrong { border-color: var(--bad); background: var(--bad-soft); }
.feedback-title { font-weight: 800; }
.feedback-right .feedback-title { color: var(--good); }
.feedback-wrong .feedback-title { color: var(--bad); }
.feedback-answer { display: flex; align-items: center; gap: 10px; font-weight: 600; }
.feedback-explain { color: var(--text-soft); }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } }

.quiz-nav {
  position: sticky; bottom: 0; z-index: 5;
  display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 8px;
  margin: 20px calc(-1 * var(--gutter)) 0; padding: 10px var(--gutter) calc(10px + env(safe-area-inset-bottom));
  background: var(--nav-bg); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  border-top: 1px solid var(--line);
}
.quiz-nav > :first-child { justify-self: start; }
.quiz-nav > :last-child { justify-self: end; }
.quiz-nav .btn-primary { min-width: 8.5rem; }
@media (max-width: 380px) {
  .quiz-nav { gap: 4px; }
  .quiz-nav .btn { padding: 0 12px; font-size: 0.9rem; }
  .quiz-nav .btn-primary { min-width: 0; }
  .quiz-nav .btn-flag { min-width: 44px; }
  .quiz-nav .flag-text { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
}
.btn-flag[aria-pressed="true"] { color: var(--accent-text); background: var(--accent-soft); }
.flag-icon {
  width: 12px; height: 14px; border-left: 2px solid currentColor; position: relative;
}
.flag-icon::after {
  content: ""; position: absolute; left: 0; top: 0; width: 10px; height: 7px;
  border: 2px solid currentColor; border-left: 0;
}
.btn-flag[aria-pressed="true"] .flag-icon::after { background: currentColor; }

.navigator { margin-top: 20px; border-top: 1px solid var(--line); }
.navigator summary {
  display: flex; align-items: center; min-height: var(--tap); cursor: pointer; padding-block: 8px;
  font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted);
}
.navigator summary:hover { color: var(--text); }
.navigator-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(44px, 1fr)); gap: 6px; padding-block: 8px 12px; }
.nav-cell {
  position: relative; width: 100%; min-height: var(--tap); border-radius: 10px; border: 1px solid var(--line);
  background: transparent; font-family: var(--font-mono); font-size: 0.85rem; cursor: pointer; color: var(--muted);
}
.nav-cell:hover { border-color: var(--line-strong); color: var(--text); }
.nav-cell.is-answered { background: var(--surface-2); color: var(--text); border-color: var(--line-strong); }
.nav-cell.is-correct { color: var(--good); border-color: var(--good); background: var(--good-soft); }
.nav-cell.is-wrong { color: var(--bad); border-color: var(--bad); background: var(--bad-soft); }
.nav-cell.is-flagged::after { content: ""; position: absolute; top: 4px; right: 4px; width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }
.nav-cell[aria-current="step"] { box-shadow: 0 0 0 2px var(--accent); color: var(--text); }
.navigator-foot { display: flex; justify-content: flex-end; padding-bottom: 8px; }

/* ---------- results ---------- */
.score-hero { display: grid; gap: 24px; justify-items: start; padding-block: 24px 28px; border-bottom: 1px solid var(--line); }
.score-ring { position: relative; width: 168px; height: 168px; }
.score-ring-label { position: absolute; inset: 0; display: grid; place-content: center; text-align: center; }
.score-pct { font-family: var(--font-display); font-size: 2.6rem; line-height: 1; }
.score-frac { font-family: var(--font-mono); font-size: 0.85rem; color: var(--muted); margin-top: 4px; }
.score-copy h1 { font-size: clamp(1.8rem, 6vw, 2.6rem); }
.score-copy .note { margin-top: 14px; }
.result-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }

.bars { border-top: 1px solid var(--line); }
.bar-row {
  display: grid; grid-template-columns: 1fr auto; grid-template-areas: "label value" "track track";
  gap: 6px 12px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--line);
}
.bar-label { grid-area: label; min-width: 0; }
.bar-value { grid-area: value; font-family: var(--font-mono); font-weight: 700; }
.bar-track { grid-area: track; height: 6px; border-radius: 6px; background: var(--line); overflow: hidden; }
.bar-fill { display: block; height: 100%; background: var(--accent); transform-origin: left center; }

.tabs { display: inline-flex; padding: 3px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface); }
.tab {
  min-height: var(--tap); padding: 0 14px; border-radius: 9px; border: 0; background: transparent;
  color: var(--muted); font-weight: 600; cursor: pointer; font-size: 0.9rem;
}
.tab[aria-pressed="true"] { background: var(--surface-3); color: var(--text); }
.review > .muted { margin-bottom: 8px; }
.review-list { border-top: 1px solid var(--line); }
.review-item { padding: 20px 0; border-bottom: 1px solid var(--line); display: grid; gap: 10px; }
.review-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 0.8rem; }
.review-num { font-family: var(--font-mono); color: var(--muted); }
.review-status { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; padding: 2px 8px; border-radius: 999px; }
.review-status.ok { color: var(--good); background: var(--good-soft); }
.review-status.bad { color: var(--bad); background: var(--bad-soft); }
.review-flag { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent-text); }
.review-q { font-size: 1.12rem; font-weight: 650; line-height: 1.4; }
.answer-line { display: grid; grid-template-columns: 6.5rem auto 1fr; align-items: center; gap: 10px; }
.answer-kind { font-size: 0.8rem; color: var(--muted); }
.answer-chosen .option-letter { background: var(--bad); border-color: var(--bad); color: var(--bg); }
.answer-chosen .answer-text { color: var(--bad); text-decoration: line-through; text-decoration-thickness: 1px; }
.answer-right .option-letter { background: var(--good); border-color: var(--good); color: var(--bg); }
.answer-right .answer-text { font-weight: 600; }
.answer-none { grid-template-columns: 6.5rem 1fr; }
.answer-none .answer-text { color: var(--muted); font-style: italic; }
.review-explain { color: var(--text-soft); padding: 12px 14px; border-radius: var(--radius-sm); background: var(--surface); border: 1px solid var(--line); }
.review-empty { padding: 20px 0; color: var(--muted); }

.empty { padding-block: 40px; display: grid; gap: 16px; justify-items: start; }

/* ---------- weak spots ---------- */
.boxes { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 8px; align-items: start; }
.box { display: grid; gap: 8px; justify-items: center; text-align: center; }
.box-count { font-family: var(--font-mono); font-weight: 700; font-size: 1.05rem; }
.box-track { display: flex; align-items: flex-end; width: 100%; max-width: 64px; height: 120px; border-radius: 8px; background: var(--surface-2); overflow: hidden; }
.box-col { display: block; width: 100%; height: 100%; transform-origin: bottom center; border-radius: 8px 8px 0 0; }
.box-1 { background: var(--bad); }
.box-2 { background: color-mix(in srgb, var(--bad) 55%, var(--accent)); }
.box-3 { background: var(--accent); }
.box-4 { background: color-mix(in srgb, var(--accent) 45%, var(--good)); }
.box-5 { background: var(--good); }
.box-name { display: grid; gap: 2px; font-size: 0.8rem; line-height: 1.25; }
.box-num { font-family: var(--font-mono); font-weight: 700; white-space: nowrap; }
@media (max-width: 399px) {
  .boxes { gap: 6px; }
  .box-name .muted { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
}

/* ---------- dialog ---------- */
.dialog {
  width: min(28rem, calc(100vw - 2 * var(--gutter))); padding: 0; border-radius: 18px;
  border: 1px solid var(--line-strong); background: var(--surface); color: var(--text); box-shadow: var(--shadow);
}
.dialog::backdrop { background: rgba(3, 6, 15, 0.7); -webkit-backdrop-filter: blur(3px); backdrop-filter: blur(3px); }
.dialog-body { display: grid; gap: 12px; padding: 22px; }
.dialog-title { font-family: var(--font-display); font-size: 1.5rem; font-weight: 600; }
.dialog-text { color: var(--text-soft); }
.dialog-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; margin-top: 8px; }
.error-panel { margin-top: 32px; display: grid; gap: 12px; justify-items: start; }

/* ---------- course picker (site root) ---------- */
.picker { max-width: 760px; padding-top: 48px; }
.course-list { border-top: 1px solid var(--line); }
.course {
  display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 18px;
  padding: 24px 4px; border-bottom: 1px solid var(--line); text-decoration: none;
}
.course .brand-mark { width: 34px; height: 34px; }
.course-body { display: grid; gap: 2px; min-width: 0; }
.course-title { font-family: var(--font-display); font-size: clamp(1.6rem, 6vw, 2.2rem); line-height: 1.15; color: var(--accent-text); }
.course .action-arrow { grid-column: 3; grid-row: 1; background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.course:hover .action-arrow, .course:focus-visible .action-arrow { transform: translateX(4px); }

@media (max-width: 519px) {
  .quiz-mode { display: none; }
}

/* ---------- larger screens ---------- */
@media (min-width: 640px) {
  :root { --gutter: 24px; }
  .btn-wide { width: auto; min-width: 14rem; justify-self: start; }
  .setup-footer { grid-template-columns: 1fr auto; align-items: center; }
  .setup-footer .note { grid-column: 1 / -1; grid-row: 2; }
  .setup-footer .btn-wide { grid-column: 2; grid-row: 1; }
  .bar-row { grid-template-columns: minmax(12rem, 18rem) 1fr 3.5rem; grid-template-areas: "label track value"; }
  .bar-value { text-align: right; }
}
@media (min-width: 800px) {
  .hero { grid-template-columns: 1fr auto; align-items: center; padding-block: 48px 52px; }
  .hero-stat { flex-direction: column; text-align: center; padding-inline: 40px; }
  .hero-stat-text { align-items: center; }
  .orbit { left: 50%; top: 56px; width: 300px; height: 300px; margin: -150px 0 0 -150px; }
  .actions { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 0; border-bottom: 1px solid var(--line); }
  .action { border-bottom: 0; padding: 28px 24px 28px 0; grid-template-columns: 1fr; grid-template-rows: auto auto 1fr auto; }
  .action + .action { padding-left: 24px; border-left: 1px solid var(--line); }
  .action .action-arrow { grid-column: 1; grid-row: 4; margin-top: 18px; }
  .score-hero { grid-template-columns: auto 1fr; align-items: center; gap: 40px; }
  .quiz-nav { position: static; margin-inline: 0; padding-inline: 0; background: transparent; border-top: 0; backdrop-filter: none; -webkit-backdrop-filter: none; }
}

/* ---------- motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .stars-2, .stars-3, .orbit-body, .timer.is-critical { animation: none !important; }
}

/* ---------- legal pages (privacy.html, terms.html) ---------- */
.view.legal { max-width: calc(65ch + 2 * var(--gutter)); padding-top: 16px; }
.legal h1 { font-family: var(--font-display); font-size: clamp(1.75rem, 6vw, 2.4rem); margin-top: 8px; }
.legal h2 { font-size: 1.2rem; margin-top: 2rem; margin-bottom: 0.5rem; color: var(--text); }
.legal p { margin-top: 0.75rem; color: var(--text-soft); line-height: 1.65; overflow-wrap: anywhere; }
.legal ul { list-style: disc; padding-left: 1.25rem; margin-top: 0.75rem; color: var(--text-soft); }
.legal li { margin-top: 0.35rem; }
.legal a { color: var(--accent-text); text-underline-offset: 3px; }
.legal a:hover { color: var(--text); }
.legal .legal-back { margin-top: 0; }
.legal .legal-back a, .legal .legal-switch a { display: inline-flex; align-items: center; min-height: var(--tap); }
.legal .legal-updated { margin-top: 0.5rem; color: var(--muted); font-size: 0.9rem; }
.legal .legal-switch { margin-top: 2.5rem; padding-top: 0.5rem; border-top: 1px solid var(--line); }