:root,
[data-theme="midnight"] {
  --bg: #0b1220;
  --bg2: #111a2b;
  --surface: #162033;
  --surface-2: #1c2a42;
  --panel: var(--surface);
  --panel2: var(--surface-2);
  --border: #2a3a55;
  --line: var(--border);
  --text: #eaf0ff;
  --muted: #a8b8d6;
  --accent: #4da3ff;
  --accent-2: #8b7bff;
  --accent2: var(--accent-2);
  --success: #3dd68c;
  --danger: #ff6b7a;
  --good: var(--success);
  --bad: var(--danger);
  --warn: #ffc14d;
  --on-accent: #071018;
  --input-bg: #0d1524;
  --top-bg: color-mix(in srgb, var(--bg) 86%, transparent);
  --nav-bg: color-mix(in srgb, var(--bg) 94%, transparent);
  --sidebar-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --cta-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --glow-1: rgba(77,163,255,.14);
  --glow-2: rgba(139,123,255,.12);
  --lead: #d7e3f8;
  --code: #cfe3ff;
  --focus: #7ec2ff;
  --shadow: 0 18px 50px rgba(0,0,0,.35);
  --radius: 18px;
  --font: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --safe-t: env(safe-area-inset-top, 0px);
  --safe-b: env(safe-area-inset-bottom, 0px);
  --safe-l: env(safe-area-inset-left, 0px);
  --safe-r: env(safe-area-inset-right, 0px);
  --sidebar: 250px;
  --bottom-nav-h: 0px;
  --sticky-cta-h: 0px;
}

[data-theme="sand"] {
  --bg: #f6f0e6;
  --bg2: #efe6d8;
  --surface: #fffaf3;
  --surface-2: #f3e9db;
  --border: #e0d0ba;
  --text: #2a241c;
  --muted: #6b5e4e;
  --accent: #c4783a;
  --accent-2: #a65d2e;
  --success: #2f8f5b;
  --danger: #c43c3c;
  --warn: #b8860b;
  --on-accent: #fffaf3;
  --input-bg: #fffdf9;
  --top-bg: color-mix(in srgb, var(--bg) 90%, transparent);
  --nav-bg: color-mix(in srgb, var(--surface) 94%, transparent);
  --sidebar-bg: color-mix(in srgb, var(--surface) 96%, transparent);
  --cta-bg: color-mix(in srgb, var(--surface) 94%, transparent);
  --glow-1: rgba(196,120,58,.12);
  --glow-2: rgba(166,93,46,.08);
  --lead: #3d3428;
  --code: #6b4520;
  --focus: #c4783a;
  --shadow: 0 14px 40px rgba(80,50,20,.12);
}

[data-theme="ocean"] {
  --bg: #071b24;
  --bg2: #0a2430;
  --surface: #0e2c38;
  --surface-2: #143847;
  --border: #1e4554;
  --text: #e6f7fb;
  --muted: #8bb8c4;
  --accent: #2ec4b6;
  --accent-2: #3d9cf0;
  --success: #3dd68c;
  --danger: #ff6b7a;
  --warn: #ffc14d;
  --on-accent: #042018;
  --input-bg: #081820;
  --top-bg: color-mix(in srgb, var(--bg) 86%, transparent);
  --nav-bg: color-mix(in srgb, var(--bg) 94%, transparent);
  --sidebar-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --cta-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --glow-1: rgba(46,196,182,.14);
  --glow-2: rgba(61,156,240,.12);
  --lead: #d2eef4;
  --code: #b8e8e2;
  --focus: #5ee0d4;
  --shadow: 0 18px 50px rgba(0,0,0,.4);
}

[data-theme="forest"] {
  --bg: #0c1410;
  --bg2: #101a14;
  --surface: #15241c;
  --surface-2: #1c2f24;
  --border: #2a4034;
  --text: #e8f5ec;
  --muted: #8fafa0;
  --accent: #5ecf8a;
  --accent-2: #c9b458;
  --success: #5ecf8a;
  --danger: #ff7a6e;
  --warn: #e0c35a;
  --on-accent: #0a160f;
  --input-bg: #0a120d;
  --top-bg: color-mix(in srgb, var(--bg) 86%, transparent);
  --nav-bg: color-mix(in srgb, var(--bg) 94%, transparent);
  --sidebar-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --cta-bg: color-mix(in srgb, var(--bg) 92%, transparent);
  --glow-1: rgba(94,207,138,.12);
  --glow-2: rgba(201,180,88,.1);
  --lead: #d8ecdf;
  --code: #c5ebd4;
  --focus: #7ee0a4;
  --shadow: 0 18px 50px rgba(0,0,0,.38);
}

[data-theme="high-contrast"] {
  --bg: #000000;
  --bg2: #0a0a0a;
  --surface: #121212;
  --surface-2: #1a1a1a;
  --border: #ffffff;
  --text: #ffffff;
  --muted: #d0d0d0;
  --accent: #ffff00;
  --accent-2: #00ffff;
  --success: #00ff66;
  --danger: #ff3333;
  --warn: #ffcc00;
  --on-accent: #000000;
  --input-bg: #000000;
  --top-bg: #000000;
  --nav-bg: #000000;
  --sidebar-bg: #000000;
  --cta-bg: #000000;
  --glow-1: transparent;
  --glow-2: transparent;
  --lead: #ffffff;
  --code: #ffff00;
  --focus: #ffff00;
  --shadow: 0 0 0 2px #fff;
}

* { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  overflow-x: clip;
}
body {
  margin: 0;
  min-height: 100dvh;
  max-width: 100vw;
  overflow-x: clip;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(900px 500px at 0% 0%, var(--glow-1), transparent 55%),
    radial-gradient(800px 480px at 100% 0%, var(--glow-2), transparent 50%),
    var(--bg);
  line-height: 1.5;
  font-size: 16px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1,h2,h3 { line-height: 1.2; letter-spacing: -.02em; }
h1 { font-size: clamp(1.45rem, 4vw, 1.9rem); margin: 0 0 .4rem; }
h2 { font-size: 1.15rem; margin: 0 0 .75rem; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.lead { color: var(--lead); }
.eyebrow {
  margin: 0 0 .35rem;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
}
code { font-family: var(--mono); font-size: .9em; color: var(--code); }

button, .btn, input, textarea, select { font: inherit; font-size: 16px; }
button, .btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .4rem;
  min-height: 44px; padding: .7rem 1.05rem; border-radius: 999px;
  border: 1px solid transparent; cursor: pointer; color: var(--text);
  background: var(--surface-2); text-decoration: none; touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
button:hover, .btn:hover { text-decoration: none; filter: brightness(1.05); }
button:disabled, .btn:disabled { opacity: .55; cursor: not-allowed; filter: none; }
.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--on-accent); font-weight: 700;
}
.ghost { background: transparent; border-color: var(--border); }
.danger {
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  color: var(--danger);
  border: 1px solid color-mix(in srgb, var(--danger) 40%, transparent);
}

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
button:focus-visible, .btn:focus-visible, .option:focus-visible, .rail-item:focus-visible,
.bottom-nav a:focus-visible, .chat-fab:focus-visible, .theme-option:focus-within {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
a:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 4px;
}

.shell { display: grid; grid-template-columns: var(--sidebar) 1fr; min-height: 100dvh; }
.sidebar {
  position: sticky; top: 0; height: 100dvh; padding: 1.1rem;
  border-right: 1px solid var(--border); background: var(--sidebar-bg);
  display: flex; flex-direction: column; gap: 1.25rem;
}
.logo { display: flex; gap: .75rem; align-items: center; }
.logo .mark {
  width: 42px; height: 42px; border-radius: 14px; display: grid; place-items: center;
  font-weight: 800; color: var(--on-accent);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.logo strong { display: block; }
.logo span { color: var(--muted); font-size: .85rem; }
.side-nav { display: grid; gap: .35rem; }
.side-nav a {
  padding: .8rem .95rem; border-radius: 12px; color: var(--muted); text-decoration: none;
  border: 1px solid transparent; min-height: 44px; display: flex; align-items: center;
}
.side-nav a.active, .side-nav a:hover {
  background: var(--surface); color: var(--text); border-color: var(--border); text-decoration: none;
}
.side-foot { margin-top: auto; color: var(--muted); font-size: .78rem; }
.main { min-width: 0; }
.top {
  display: flex; align-items: center; gap: .75rem;
  padding: .85rem 1.25rem; border-bottom: 1px solid var(--border);
  position: sticky; top: 0; background: var(--top-bg); backdrop-filter: blur(10px); z-index: 10;
}
.top-title { font-weight: 700; }
.nav-toggle { display: none; }
.content {
  padding: 1.25rem;
  max-width: 1100px;
  padding-bottom: calc(1.25rem + var(--sticky-cta-h));
}

.hero, .book-hero, .page-head {
  display: flex; justify-content: space-between; gap: 1rem; align-items: flex-start;
  margin-bottom: 1.25rem; flex-wrap: wrap;
}
.grid.books {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 1rem;
}
.book-card {
  display: grid; grid-template-columns: 14px 1fr; overflow: hidden;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface);
  box-shadow: var(--shadow); color: inherit; text-decoration: none; min-height: 160px;
}
.book-card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); text-decoration: none; }
.book-spine { background: linear-gradient(180deg, var(--accent), var(--accent-2)); }
.book-body { padding: 1rem; min-width: 0; }
.book-body h3 { margin: .35rem 0; font-size: 1.05rem; overflow-wrap: anywhere; }
.meta { color: var(--muted); font-size: .86rem; margin-top: .55rem; }
.pill {
  display: inline-flex; align-items: center; padding: .25rem .6rem; border-radius: 999px;
  font-size: .72rem; text-transform: uppercase; letter-spacing: .06em; font-weight: 700;
  border: 1px solid var(--border); color: var(--muted); width: fit-content;
}
.pill.ready {
  color: var(--success);
  border-color: color-mix(in srgb, var(--success) 45%, transparent);
  background: color-mix(in srgb, var(--success) 10%, transparent);
}
.pill.extracting, .pill.uploaded, .pill.generating {
  color: var(--warn);
  border-color: color-mix(in srgb, var(--warn) 45%, transparent);
  background: color-mix(in srgb, var(--warn) 10%, transparent);
}
.pill.error {
  color: var(--danger);
  border-color: color-mix(in srgb, var(--danger) 45%, transparent);
  background: color-mix(in srgb, var(--danger) 10%, transparent);
}

.panel {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.1rem; box-shadow: var(--shadow); margin-bottom: 1rem;
}
.panel.compact { padding: .95rem 1rem; }
.empty {
  border: 1px dashed var(--border); border-radius: var(--radius); padding: 2rem; text-align: center; color: var(--muted);
}
.empty-cta {
  display: grid; gap: .65rem; justify-items: center;
  background: color-mix(in srgb, var(--surface) 55%, transparent); padding: 2.25rem 1.25rem;
}
.empty-cta h2 { margin: 0; color: var(--text); }
.empty-icon { font-size: 2rem; line-height: 1; }
.empty-cta .primary, .empty-cta .btn { margin-top: .35rem; min-width: min(200px, 100%); }

.day-list { display: grid; gap: .75rem; }
.day-card {
  display: grid; grid-template-columns: 72px 1fr auto; gap: 1rem; align-items: center;
  background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 1rem;
}
.day-card.locked { opacity: .55; }
.day-card.is-next {
  border-color: color-mix(in srgb, var(--accent) 55%, var(--border));
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 25%, transparent);
}
.day-num {
  width: 64px; height: 64px; border-radius: 16px; display: grid; place-items: center;
  background: var(--bg2); border: 1px solid var(--border); font-weight: 800; color: var(--accent);
  text-align: center; font-size: .78rem; padding: .25rem;
}
.day-actions { display: flex; gap: .45rem; flex-wrap: wrap; justify-content: flex-end; }
.day-progress .progress-line { margin: .75rem 0 0; }
.back { color: var(--muted); font-size: .92rem; display: inline-block; margin-bottom: .5rem; min-height: 28px; }

.alert, .toast {
  margin-top: .75rem; padding: .8rem 1rem; border-radius: 12px;
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--danger) 40%, transparent);
  color: var(--text);
}
.toast.ok {
  background: color-mix(in srgb, var(--success) 12%, transparent);
  border-color: color-mix(in srgb, var(--success) 40%, transparent);
}
.banner-toast { margin: 0 0 1rem; transition: opacity .35s ease, transform .35s ease; }
.banner-toast.fade-out { opacity: 0; transform: translateY(-6px); }
.toast-host {
  position: fixed; left: 50%; bottom: calc(1rem + var(--safe-b) + var(--bottom-nav-h) + var(--sticky-cta-h));
  transform: translateX(-50%); z-index: 60; display: grid; gap: .5rem; width: min(420px, calc(100% - 2rem));
  pointer-events: none;
}
.floating-toast {
  margin: 0; opacity: 0; transform: translateY(8px); transition: opacity .25s ease, transform .25s ease;
  pointer-events: none; text-align: center; box-shadow: var(--shadow);
}
.floating-toast.show { opacity: 1; transform: translateY(0); }

.generating { display: flex; gap: 1rem; align-items: center; }
.spinner {
  width: 28px; height: 28px; border-radius: 50%; flex: 0 0 auto;
  border: 3px solid var(--border); border-top-color: var(--accent); animation: spin 800ms linear infinite;
}
.btn-spinner {
  width: 16px; height: 16px; border-radius: 50%;
  border: 2px solid color-mix(in srgb, var(--on-accent) 25%, transparent);
  border-top-color: var(--on-accent);
  animation: spin 700ms linear infinite; display: inline-block;
}
@keyframes spin { to { transform: rotate(360deg); } }

.habit {
  margin-bottom: 1rem; padding: .85rem 1rem; border-radius: 14px;
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  color: var(--lead);
}
.train-progress { margin-bottom: 1rem; }
.train-layout { display: grid; grid-template-columns: 220px 1fr; gap: 1rem; }
.concept-rail {
  display: flex; flex-direction: column; gap: .4rem; position: sticky; top: 72px; align-self: start;
}
.rail-item {
  text-align: left; border-radius: 12px; background: var(--bg2); border: 1px solid var(--border); color: var(--muted);
  min-height: 44px;
}
.rail-item.active { color: var(--text); border-color: var(--accent); background: var(--surface); }
.concept-pane .concept { display: none; }
.concept-pane .concept.show { display: block; }
.concept-pane blockquote {
  margin: 0 0 1rem; padding: .9rem 1rem; border-left: 3px solid var(--accent-2);
  background: color-mix(in srgb, var(--accent-2) 10%, transparent);
  border-radius: 0 12px 12px 0; color: var(--lead); font-style: italic;
}
.concept-pane ul { color: var(--muted); }
.explanation { margin: 0 0 1rem; color: var(--lead); }
.explanation p { margin: 0 0 .75rem; }
.explanation p:last-child { margin-bottom: 0; }
.glossary {
  margin: 1rem 0;
  padding: .95rem 1rem;
  border-radius: 14px;
  background: color-mix(in srgb, var(--accent-2) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent-2) 28%, transparent);
}
.glossary h3, .section-label {
  margin: 0 0 .65rem;
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  display: flex; align-items: center; gap: .35rem;
}
.glossary dl { margin: 0; display: grid; gap: .65rem; }
.glossary-item { display: grid; gap: .15rem; }
.glossary dt { font-weight: 700; color: var(--text); }
.glossary dd { margin: 0; color: var(--muted); font-size: .95rem; }
.concept-habit {
  margin: 1rem 0 0;
  padding: .75rem .95rem;
  border-radius: 12px;
  background: color-mix(in srgb, var(--success) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--success) 28%, transparent);
  color: var(--lead);
  font-size: .95rem;
}
.concept-habit p { margin: 0; }
.viz {
  margin-top: 1rem; border: 1px solid var(--border); border-radius: 14px; background: var(--input-bg); padding: 1rem;
}
.viz-title { font-size: .72rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); font-weight: 700; margin-bottom: .7rem; }
.sys-grid { display: grid; grid-template-columns: 1fr; gap: .65rem; }
.sys-card { border-radius: 14px; padding: .9rem; border: 1px solid var(--border); }
.sys-card.s1 { background: color-mix(in srgb, #ff8f5a 12%, transparent); border-color: color-mix(in srgb, #ff8f5a 35%, transparent); }
.sys-card.s2 { background: color-mix(in srgb, #5ad0ff 12%, transparent); border-color: color-mix(in srgb, #5ad0ff 35%, transparent); }
.stack-item {
  display: flex; justify-content: space-between; gap: .75rem; padding: .7rem .85rem; margin-bottom: .45rem;
  border-radius: 12px; background: var(--surface-2); border: 1px solid var(--border); font-size: .92rem;
}
.stack-item span:last-child { color: var(--muted); font-family: var(--mono); font-size: .78rem; }

/* Sticky primary CTA bar (Train / Quiz) */
.sticky-cta {
  display: flex; gap: .55rem; flex-wrap: wrap; align-items: center; justify-content: space-between;
  margin-top: 1rem;
}
.train-cta, .quiz-cta {
  position: sticky;
  bottom: calc(var(--bottom-nav-h) + var(--safe-b) + .5rem);
  z-index: 20;
  padding: .65rem .75rem;
  margin-left: -.25rem; margin-right: -.25rem;
  background: var(--cta-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}
.train-cta .primary, .quiz-cta .primary { flex: 1; min-width: 140px; }
.train-cta .ghost, .quiz-cta .ghost { flex: 0 0 auto; }
body.has-sticky-cta { --sticky-cta-h: 72px; }
.hide-mobile { display: inline-flex; }

.q-card {
  border: 1px solid var(--border); border-radius: 16px; padding: 1.05rem; background: var(--surface); margin-bottom: .85rem;
  transition: border-color .15s ease, box-shadow .15s ease;
}
.q-card.q-ok { border-color: color-mix(in srgb, var(--success) 45%, transparent); }
.q-card.q-wrong { border-color: color-mix(in srgb, var(--danger) 45%, transparent); }
.q-type { font-size: .7rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); font-weight: 700; }
.q-prompt { margin: .35rem 0 .55rem; font-size: 1.05rem; font-weight: 700; overflow-wrap: anywhere; }
.options { display: grid; gap: .5rem; margin-top: .65rem; }
.option {
  text-align: left; border-radius: 12px; border: 1px solid var(--border); background: var(--input-bg); color: var(--text);
  min-height: 48px; padding: .85rem 1rem; width: 100%; overflow-wrap: anywhere;
}
.option.selected {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--accent) 35%, transparent);
}
.option.correct { border-color: var(--success); background: color-mix(in srgb, var(--success) 12%, transparent); }
.option.wrong { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 10%, transparent); }
.explain {
  margin-top: .75rem; padding: .8rem .9rem; border-radius: 12px;
  border: 1px solid var(--border); color: var(--muted); font-size: .92rem; overflow-wrap: anywhere;
}
.explain-ok {
  border-color: color-mix(in srgb, var(--success) 35%, transparent);
  background: color-mix(in srgb, var(--success) 8%, transparent);
  color: var(--text);
}
.explain-bad {
  border-color: color-mix(in srgb, var(--danger) 35%, transparent);
  background: color-mix(in srgb, var(--danger) 8%, transparent);
  color: var(--text);
}
.review-link { font-weight: 700; white-space: nowrap; }
.progress-line {
  height: 8px; border-radius: 999px; background: var(--input-bg); border: 1px solid var(--border);
  overflow: hidden; margin-bottom: 1rem;
}
.progress-line > span {
  display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--success));
  transition: width .25s ease;
}
.quiz-status { margin-bottom: .35rem; }
.results-panel { margin-top: 1.25rem; text-align: center; }
.results-msg { margin: .75rem 0 1rem; color: var(--muted); }
.score-ring {
  position: relative; width: 120px; height: 120px; margin: 0 auto .5rem;
}
.score-ring svg { transform: rotate(-90deg); display: block; }
.ring-bg { fill: none; stroke: var(--border); stroke-width: 10; }
.ring-fg {
  fill: none; stroke-width: 10; stroke-linecap: round;
  transition: stroke-dashoffset .5s ease;
}
.score-ring-label {
  position: absolute; inset: 0; display: grid; place-content: center; text-align: center; gap: .1rem;
}
.score-pct { font-size: 1.65rem; font-weight: 800; line-height: 1.1; }
.score-big { font-size: 2rem; font-weight: 800; }
.wrong-list { text-align: left; margin: 0 0 1rem; padding: .85rem 1rem; border-radius: 12px; background: var(--bg2); border: 1px solid var(--border); }
.wrong-list ul { margin: .35rem 0 0; padding-left: 1.1rem; color: var(--muted); }
.wrong-list li { margin: .35rem 0; }

.export, textarea.export {
  width: 100%; min-height: 140px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--input-bg); color: var(--text); padding: .8rem; font-family: var(--mono); font-size: .82rem;
}
.row { display: flex; gap: .55rem; flex-wrap: wrap; align-items: center; }
.row.between { justify-content: space-between; }
.row.wrap { flex-wrap: wrap; }
.actions-col { display: grid; gap: .5rem; }
.stack { display: grid; gap: 1rem; }

.modal { border: none; padding: 0; background: transparent; max-width: 520px; width: calc(100% - 2rem); }
.modal::backdrop { background: rgba(0,0,0,.55); }
.modal-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 18px; padding: 1.2rem; box-shadow: var(--shadow);
  display: grid; gap: .75rem;
}
.upload-busy {
  display: flex; align-items: center; gap: .75rem; color: var(--muted); font-size: .92rem;
}
label { display: grid; gap: .35rem; color: var(--muted); font-size: .9rem; }
input[type=text], input[type=password], input[type=number], input[type=file] {
  width: 100%; min-height: 44px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--input-bg); color: var(--text); padding: .7rem .85rem;
}
.settings-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 1rem; }
.form .half { flex: 1; min-width: 140px; }
.steps { padding-left: 1.15rem; color: var(--lead); }
.steps li { margin: .55rem 0; }
.callout {
  margin-top: 1rem; padding: .9rem 1rem; border-radius: 14px; background: var(--bg2); border: 1px solid var(--border);
}
.test-out {
  margin-top: .75rem; padding: .8rem; border-radius: 12px; background: var(--input-bg); border: 1px solid var(--border);
  white-space: pre-wrap; font-family: var(--mono); font-size: .82rem;
}
.test-out.ok { border-color: color-mix(in srgb, var(--success) 45%, transparent); color: var(--success); }
.test-out.bad { border-color: color-mix(in srgb, var(--danger) 45%, transparent); color: var(--danger); }
.scrim { display: none; }
.sticky-save { margin-top: .5rem; }

/* Theme picker */
.theme-picker {
  border: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: .65rem;
}
.theme-option {
  display: grid; gap: .45rem; justify-items: start;
  padding: .75rem; border-radius: 14px; border: 1px solid var(--border);
  background: var(--bg2); cursor: pointer; color: var(--text);
  min-height: 88px; touch-action: manipulation;
}
.theme-option input { position: absolute; opacity: 0; pointer-events: none; }
.theme-option.is-selected,
.theme-option:has(input:checked) {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 40%, transparent);
  background: var(--surface);
}
.theme-swatch {
  display: flex; width: 100%; height: 28px; border-radius: 999px; overflow: hidden;
  border: 1px solid var(--border);
}
.theme-swatch i { flex: 1; display: block; }
.theme-name { font-weight: 700; font-size: .92rem; }

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

.bottom-nav {
  display: none;
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 35;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  padding: .35rem max(0px, var(--safe-l)) calc(.35rem + var(--safe-b)) max(0px, var(--safe-r));
  background: var(--nav-bg);
  border-top: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.bottom-nav a {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .15rem; min-height: 48px; padding: .35rem .5rem;
  color: var(--muted); text-decoration: none; font-size: .72rem; font-weight: 600;
  touch-action: manipulation; -webkit-tap-highlight-color: transparent;
  border-radius: 12px;
}
.bottom-nav a .bn-icon { font-size: 1.15rem; line-height: 1; }
.bottom-nav a.active {
  color: var(--text);
  position: relative;
}
.bottom-nav a.active::after {
  content: "";
  position: absolute; top: 4px; width: 18px; height: 3px; border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}
.bottom-nav a:hover { text-decoration: none; color: var(--text); }

.chat-fab {
  position: fixed; z-index: 45;
  right: max(1rem, var(--safe-r));
  bottom: calc(1rem + var(--safe-b) + var(--bottom-nav-h) + var(--sticky-cta-h));
  min-width: 56px; min-height: 56px; padding: 0 .95rem;
  border-radius: 999px; gap: .4rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--on-accent); font-weight: 800; border: none;
  box-shadow: 0 12px 32px color-mix(in srgb, var(--accent) 35%, transparent);
}
.chat-fab-label { font-size: .85rem; }
.chat-panel {
  position: fixed; inset: 0; z-index: 50;
  display: flex; justify-content: flex-end; align-items: stretch;
  background: rgba(0,0,0,.45);
  opacity: 0; pointer-events: none; transition: opacity .2s ease;
}
.chat-panel.open { opacity: 1; pointer-events: auto; }
.chat-sheet {
  width: min(420px, 100%);
  height: 100%; max-height: 100dvh;
  background: var(--bg2); border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  transform: translateX(8%); transition: transform .22s ease;
  padding-bottom: var(--safe-b);
}
.chat-panel.open .chat-sheet { transform: translateX(0); }
.chat-head {
  display: flex; align-items: flex-start; justify-content: space-between; gap: .75rem;
  padding: calc(.85rem + var(--safe-t)) 1rem .75rem;
  border-bottom: 1px solid var(--border);
  background: var(--top-bg);
}
.chat-close { min-width: 44px; min-height: 44px; padding: 0; border-radius: 12px; }
.chat-messages {
  flex: 1; overflow-y: auto; padding: 1rem; display: flex; flex-direction: column; gap: .65rem;
  -webkit-overflow-scrolling: touch;
}
.chat-bubble {
  max-width: 92%; padding: .75rem .9rem; border-radius: 14px;
  border: 1px solid var(--border); background: var(--surface); font-size: .95rem;
}
.chat-bubble.user {
  align-self: flex-end;
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  border-color: color-mix(in srgb, var(--accent) 35%, transparent);
}
.chat-bubble.assistant { align-self: flex-start; }
.chat-bubble.pending { opacity: .85; }
.chat-role {
  font-size: .68rem; text-transform: uppercase; letter-spacing: .06em;
  color: var(--muted); font-weight: 700; margin-bottom: .25rem;
}
.chat-body { color: var(--text); word-break: break-word; }
.chat-cta {
  margin: 0 1rem .5rem; padding: .85rem 1rem; border-radius: 14px;
  background: color-mix(in srgb, var(--warn) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--warn) 35%, transparent);
  display: grid; gap: .65rem;
}
.chat-input-row {
  display: grid; grid-template-columns: 1fr auto; gap: .5rem; align-items: end;
  padding: .75rem 1rem calc(.75rem + var(--safe-b));
  border-top: 1px solid var(--border); background: var(--top-bg);
}
.chat-input-row textarea {
  width: 100%; min-height: 44px; max-height: 120px; resize: none;
  border-radius: 14px; border: 1px solid var(--border);
  background: var(--input-bg); color: var(--text); padding: .7rem .85rem;
  line-height: 1.35;
}
.chat-input-row button { min-width: 72px; }
body.chat-open { overflow: hidden; }

.typing-dots { display: inline-flex; gap: 4px; align-items: center; height: 1rem; }
.typing-dots i {
  width: 6px; height: 6px; border-radius: 50%; background: var(--muted);
  animation: bounce 1s infinite ease-in-out;
}
.typing-dots i:nth-child(2) { animation-delay: .15s; }
.typing-dots i:nth-child(3) { animation-delay: .3s; }
@keyframes bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: .5; }
  40% { transform: translateY(-4px); opacity: 1; }
}
.chat-skeleton { display: grid; gap: .45rem; padding: .5rem 0; }
.skel-line {
  height: 12px; border-radius: 8px; width: 80%;
  background: linear-gradient(90deg, var(--surface), var(--surface-2), var(--surface));
  background-size: 200% 100%; animation: shimmer 1.2s infinite linear;
}
.skel-line.short { width: 45%; }
@keyframes shimmer {
  0% { background-position: 100% 0; }
  100% { background-position: -100% 0; }
}

.skill-list { display: grid; gap: .65rem; }
.skill-card {
  display: block; padding: .95rem 1rem; border-radius: 14px;
  border: 1px solid var(--border); background: var(--bg2); color: inherit; text-decoration: none;
  min-height: 44px;
}
.skill-card:hover {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
  text-decoration: none;
}
.skill-card-top { display: flex; justify-content: space-between; gap: .75rem; align-items: center; }
.skill-desc { margin: .45rem 0 0; }
.skill-cat-title {
  text-transform: uppercase; letter-spacing: .08em; font-size: .78rem;
  color: var(--muted); margin: 0 0 .75rem;
}
.skill-form textarea.prompt-area,
textarea.prompt-area {
  width: 100%; min-height: 180px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--input-bg); color: var(--text); padding: .8rem; font-family: var(--mono);
  font-size: .82rem; line-height: 1.45; resize: vertical;
}
select {
  width: 100%; min-height: 44px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--input-bg); color: var(--text); padding: .7rem .85rem;
}
.check-row .check-wrap {
  display: flex; align-items: center; gap: .55rem; min-height: 44px;
  color: var(--text); font-size: 1rem;
}
.check-wrap input[type=checkbox] { width: 20px; height: 20px; accent-color: var(--accent); }
.var-list { margin: .5rem 0 0; padding-left: 1.1rem; color: var(--lead); }
.var-list li { margin: .35rem 0; }
.skill-danger { margin-top: 1rem; margin-bottom: 2rem; }

[data-theme="high-contrast"] .pill,
[data-theme="high-contrast"] .book-card,
[data-theme="high-contrast"] .panel,
[data-theme="high-contrast"] .day-card,
[data-theme="high-contrast"] .q-card,
[data-theme="high-contrast"] .option,
[data-theme="high-contrast"] .bottom-nav,
[data-theme="high-contrast"] .train-cta,
[data-theme="high-contrast"] .quiz-cta,
[data-theme="high-contrast"] .theme-option {
  border-width: 2px;
}
[data-theme="high-contrast"] .primary {
  background: var(--accent);
  color: var(--on-accent);
}
[data-theme="high-contrast"] .muted { color: #d0d0d0; }

@media (max-width: 900px) {
  :root, html { --bottom-nav-h: 64px; }
  .shell { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed; inset: 0 auto 0 0; width: min(84vw, 280px); transform: translateX(-105%);
    transition: transform .2s ease; z-index: 40; height: 100dvh;
    padding-top: calc(1.1rem + var(--safe-t));
  }
  .sidebar.open { transform: translateX(0); }
  .nav-toggle { display: inline-flex; min-width: 44px; min-height: 44px; }
  .scrim.show { display: block; position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 30; }
  .bottom-nav { display: grid; }
  .top {
    padding-top: calc(.75rem + var(--safe-t));
    padding-left: max(1rem, var(--safe-l));
    padding-right: max(1rem, var(--safe-r));
  }
  .content {
    padding: 1rem max(1rem, var(--safe-l)) calc(1.25rem + var(--bottom-nav-h) + var(--safe-b) + var(--sticky-cta-h)) max(1rem, var(--safe-r));
  }
  .train-layout { grid-template-columns: 1fr; }
  .concept-rail {
    position: sticky; top: calc(56px + var(--safe-t)); z-index: 5;
    flex-direction: row; overflow-x: auto; gap: .4rem;
    padding: .45rem 0; margin: 0 -.15rem .35rem;
    background: var(--top-bg); backdrop-filter: blur(8px);
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .concept-rail::-webkit-scrollbar { display: none; }
  .rail-item { flex: 0 0 auto; white-space: nowrap; min-height: 44px; padding: .65rem .9rem; }
  .day-card { grid-template-columns: 1fr; padding: 1rem; }
  .day-actions { justify-content: stretch; }
  .day-actions .btn, .day-actions a.btn { flex: 1; min-height: 48px; text-align: center; }
  .settings-grid { grid-template-columns: 1fr; }
  .grid.books { grid-template-columns: 1fr; gap: .85rem; }
  .book-card { min-height: 140px; }
  .hero, .book-hero, .page-head { flex-direction: column; align-items: stretch; }
  .hero .primary, .book-hero .primary, .page-head .btn { width: 100%; min-height: 48px; }
  .actions-col .primary, .actions-col .danger, .actions-col button { width: 100%; }
  .option { min-height: 48px; padding: .85rem 1rem; }
  .hide-mobile { display: none !important; }
  .train-cta, .quiz-cta {
    bottom: calc(var(--bottom-nav-h) + var(--safe-b) + .35rem);
    margin-left: 0; margin-right: 0;
  }
  .chat-fab {
    right: max(.85rem, var(--safe-r));
    bottom: calc(.85rem + var(--safe-b) + var(--bottom-nav-h) + var(--sticky-cta-h));
    width: 56px; padding: 0;
  }
  .chat-fab-label { display: none; }
  /* Keep Tutor FAB clear of sticky primary CTAs */
  body.has-sticky-cta .chat-fab {
    left: max(.85rem, var(--safe-l));
    right: auto;
  }
  .chat-panel { align-items: flex-end; }
  .chat-sheet {
    width: 100%; height: min(92dvh, 100%); max-height: 92dvh;
    border-left: none; border-radius: 18px 18px 0 0;
    transform: translateY(12%);
  }
  .chat-panel.open .chat-sheet { transform: translateY(0); }
  .day-progress .primary.btn { width: 100%; }
  .theme-picker { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 480px) {
  body { font-size: 16px; }
  h1 { font-size: 1.35rem; }
  h2 { font-size: 1.05rem; }
  .content {
    padding-left: max(.85rem, var(--safe-l));
    padding-right: max(.85rem, var(--safe-r));
  }
  .panel { padding: .95rem; border-radius: 16px; }
  .book-body { padding: .9rem; }
  .q-prompt { font-size: 1rem; }
  .train-cta, .quiz-cta {
    gap: .45rem;
    padding: .55rem .6rem;
  }
  .train-cta .primary, .quiz-cta .primary { min-width: 0; min-height: 48px; }
  .train-cta .ghost, .quiz-cta .ghost { min-height: 48px; padding-inline: .85rem; }
  body.has-sticky-cta { --sticky-cta-h: 76px; }
  .bottom-nav a { font-size: .68rem; min-height: 52px; }
  .theme-picker { grid-template-columns: 1fr 1fr; gap: .55rem; }
  .theme-option { min-height: 84px; padding: .65rem; }
  .form .half { min-width: 100%; }
  .row .half { flex: 1 1 100%; }
}

@media (max-width: 400px) {
  /* ~390px phones */
  h1 { font-size: 1.28rem; }
  .top-title { font-size: .95rem; }
  .eyebrow { font-size: .68rem; }
  .day-num { width: 56px; height: 56px; font-size: .72rem; }
  .chat-fab { width: 52px; min-width: 52px; min-height: 52px; }
  .sticky-cta { flex-wrap: nowrap; }
  .train-cta .ghost, .quiz-cta .ghost { flex: 0 0 auto; }
  .train-cta .primary, .quiz-cta .primary { flex: 1 1 auto; }
}

@media (min-width: 901px) {
  .chat-fab { bottom: calc(1.25rem + var(--sticky-cta-h)); }
  body.has-chat .content { padding-right: 1.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}

/* —— Auth / login —— */
body.is-login .sidebar,
body.is-login .bottom-nav,
body.is-login .nav-toggle { display: none; }
body.is-login .shell { display: block; }
body.is-login .main { min-height: 100dvh; }
body.is-login .top { justify-content: center; }
body.is-login .content { max-width: 480px; margin: 0 auto; padding-bottom: 2rem; }

.login-wrap { display: flex; justify-content: center; padding: .5rem 0 2rem; }
.login-card { width: 100%; max-width: 420px; padding: 1.25rem 1.25rem 1.5rem; }
.login-brand { display: flex; gap: .85rem; align-items: center; margin-bottom: .75rem; }
.login-brand h1 { margin: .15rem 0 0; font-size: 1.45rem; }
.login-form { margin-top: 1rem; display: grid; gap: .85rem; }
.login-submit { width: 100%; min-height: 48px; font-size: 1.05rem; }
.login-hint { margin-top: 1.1rem; }
.login-hint summary { cursor: pointer; }
.login-hint ul { margin: .5rem 0 0; padding-left: 1.1rem; }
.login-hint code { font-family: var(--mono); font-size: .85em; }

.top { display: flex; align-items: center; gap: .65rem; }
.top-title { flex: 1 1 auto; min-width: 0; }
.top-user { display: flex; align-items: center; gap: .5rem; flex: 0 0 auto; }
.top-user-name {
  font-size: .85rem; color: var(--muted); max-width: 7.5rem;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.logout-form { margin: 0; }
.logout-form.inline { display: inline; }
.logout-btn { min-height: 40px; padding: .35rem .7rem; font-size: .85rem; }
.side-user {
  margin-top: auto; padding: .85rem 1rem 0.35rem;
  border-top: 1px solid var(--border);
}
.side-user-name { font-weight: 600; font-size: .95rem; }
.side-nav { flex: 1 1 auto; }

.bn-logout { margin: 0; flex: 1 1 0; display: flex; }
.bn-logout-btn {
  flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .15rem; background: transparent; border: 0; color: var(--muted);
  font: inherit; font-size: .72rem; min-height: 52px; cursor: pointer; padding: .35rem;
}
.bn-logout-btn .bn-icon { font-size: 1.15rem; }

.users-table { width: 100%; border-collapse: collapse; font-size: .92rem; }
.users-table th, .users-table td { text-align: left; padding: .65rem .5rem; border-bottom: 1px solid var(--border); }
.users-table th { color: var(--muted); font-weight: 600; font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; }

@media (max-width: 720px) {
  .top-user-name { display: none; }
  .login-card { padding: 1.1rem; }
}

/* —— Change password —— */
.account-wrap { display: flex; justify-content: flex-start; }
.account-card { width: 100%; max-width: 440px; padding: 1.25rem 1.25rem 1.5rem; }
.account-card h1 { margin: .15rem 0 .4rem; font-size: 1.45rem; }
.account-form { margin-top: 1rem; display: grid; gap: .85rem; }
.account-form input { font-size: 16px; width: 100%; }
.form-actions { display: grid; }
.form-actions .primary { width: 100%; min-height: 48px; }
.account-link { margin-top: .55rem; width: 100%; }

.reset-form { display: grid; gap: .45rem; min-width: 12rem; }
.reset-form input { font-size: 16px; min-height: 44px; }
.reset-form .btn { width: 100%; }

@media (max-width: 720px) {
  .account-card { padding: 1.1rem; max-width: none; }
  .users-table thead { display: none; }
  .users-table, .users-table tbody, .users-table tr, .users-table td { display: block; width: 100%; }
  .users-table tr {
    border: 1px solid var(--border);
    border-radius: 14px;
    margin: 0 0 .75rem;
    padding: .65rem .75rem .85rem;
  }
  .users-table td { border: 0; padding: .3rem 0; }
  .users-table td::before {
    content: attr(data-label);
    display: block;
    font-size: .72rem;
    font-weight: 600;
    letter-spacing: .04em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: .15rem;
  }
  .reset-form { min-width: 0; }
}