*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Surfaces — warm cream tint throughout */
  --bg:          oklch(98.5% 0.007 70);
  --parchment:   oklch(95.5% 0.016 68);
  --parchment2:  oklch(93%   0.020 66);
  --white:       oklch(99.5% 0.003 70);
  --border:      oklch(87%   0.013 65);
  --border-hi:   oklch(78%   0.016 60);

  /* Text */
  --ink:         oklch(16%   0.014 40);
  --ink-mute:    oklch(46%   0.011 42);
  --ink-dim:     oklch(64%   0.009 55);

  /* Accent — deep burgundy */
  --burg:        oklch(40%   0.20  18);
  --burg-mid:    oklch(52%   0.18  18);
  --burg-bg:     oklch(96.5% 0.05  18);
  --burg-border: oklch(88%   0.10  18);

  /* Semantic */
  --correct:     oklch(36%   0.16  155);
  --correct-bg:  oklch(95.5% 0.04  155);
  --correct-bd:  oklch(84%   0.08  155);
  --wrong:       oklch(40%   0.20  18);
  --wrong-bg:    oklch(96.5% 0.05  18);
  --wrong-bd:    oklch(88%   0.10  18);

  /* Type */
  --serif: 'Playfair Display', 'Georgia', serif;
  --sans:  'Inter', system-ui, sans-serif;

  /* Motion */
  --ease-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out:  cubic-bezier(0.25, 1, 0.5, 1);
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.screen { display: none; height: 100vh; overflow: hidden; }
.screen.active { display: flex; overflow-y: auto; }
.hidden { display: none !important; }

/* ─────────────────────────────────
   HOME
───────────────────────────────── */

#home { flex-direction: row; }

/* Left panel — parchment */
.home-left {
  width: 38%;
  min-width: 260px;
  background: var(--parchment);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
}

.home-brand {
  flex: 1;
  padding: clamp(2rem, 5vw, 3.5rem) clamp(1.75rem, 4vw, 3rem);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 2.5rem;
}

.brand-logo-mark {
  flex-shrink: 0;
  display: block;
}

.brand-logo-text {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1rem;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.brand-eyebrow {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--burg);
  margin-bottom: 0.9rem;
}

.brand-name {
  font-family: var(--serif);
  font-size: clamp(2.6rem, 5.5vw, 4rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 1.25rem;
}

.brand-name em {
  font-style: italic;
  color: var(--burg);
}

.brand-desc {
  font-size: 0.92rem;
  color: var(--ink-mute);
  line-height: 1.72;
}

/* Stats row */
.home-stats {
  display: flex;
  border-top: 1px solid var(--border);
}

.stat {
  flex: 1;
  padding: 1.1rem 1.4rem;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
}
.stat:last-child { border-right: none; }

.stat-n {
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.stat-l {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

/* Right panel */
.home-right {
  flex: 1;
  background: var(--white);
  overflow-y: auto;
  padding: clamp(2rem, 5vw, 3.5rem) clamp(1.75rem, 4vw, 3rem);
  display: flex;
  flex-direction: column;
  gap: 0;
}

.filter-bar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.filter-label {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
}

.pill {
  background: none;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.28rem 0.75rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--ink-mute);
  cursor: pointer;
  transition: border-color 120ms, color 120ms, background 120ms;
}

.pill:hover {
  border-color: var(--border-hi);
  color: var(--ink);
}

.pill.active {
  background: var(--ink);
  border-color: var(--ink);
  color: oklch(98% 0.004 40);
}

.queue-info {
  font-size: 0.82rem;
  color: var(--ink-dim);
  margin-bottom: 1.25rem;
}

.start-btn {
  align-self: flex-start;
  background: var(--burg);
  color: oklch(98% 0.004 40);
  border: none;
  border-radius: 4px;
  padding: 0.65rem 1.4rem;
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: opacity 140ms;
}
.start-btn:hover { opacity: 0.86; }
.start-btn:disabled { opacity: 0.35; cursor: default; }

.loading-msg {
  font-size: 0.85rem;
  color: var(--ink-mute);
  font-style: italic;
}

/* ─────────────────────────────────
   QUIZ
───────────────────────────────── */

#quiz { flex-direction: column; background: var(--white); }

.quiz-header {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 0.9rem 2rem;
  border-bottom: 1px solid var(--border);
  background: var(--parchment);
  flex-shrink: 0;
}

.back-btn {
  background: none;
  border: none;
  color: var(--ink-dim);
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 500;
  cursor: pointer;
  transition: color 130ms;
  white-space: nowrap;
  padding: 0;
}
.back-btn:hover { color: var(--ink); }

.quiz-meta {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.quiz-topic {
  font-size: 0.67rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

.quiz-progress-wrap {
  height: 1px;
  background: var(--border);
}

.quiz-progress-fill {
  height: 100%;
  background: var(--burg);
  transition: width 420ms var(--ease-expo);
  width: 0%;
}

.quiz-counter {
  font-size: 0.78rem;
  color: var(--ink-dim);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* Quiz body */
.quiz-body {
  flex: 1;
  overflow-y: auto;
  padding: clamp(2rem, 5vw, 3rem) clamp(1.5rem, 5vw, 2.5rem);
  display: flex;
  justify-content: center;
}

.quiz-body::-webkit-scrollbar { width: 3px; }
.quiz-body::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* Question card — no box, just type */
.q-card {
  width: 100%;
  max-width: 640px;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  animation: rise 340ms var(--ease-expo) both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

.q-meta {
  display: flex;
  align-items: center;
  gap: 0.55rem;
}

.q-category {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--burg);
  background: var(--burg-bg);
  border: 1px solid var(--burg-border);
  border-radius: 5px;
  padding: 0.18rem 0.55rem;
}

.q-difficulty {
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-dim);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 0.18rem 0.55rem;
  background: var(--bg);
}

.q-vignette {
  font-size: 0.95rem;
  color: var(--ink-mute);
  line-height: 1.78;
  padding: 0.85rem 1rem;
  background: oklch(97% 0.006 250);
  border: 1px solid oklch(90% 0.010 250);
  border-radius: 8px;
}

.q-stem {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.55;
}

/* Options */
.options {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.opt {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  padding: 0.85rem 1rem;
  background: var(--white);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 0.92rem;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
  width: 100%;
  transition: border-color 120ms, background 120ms, box-shadow 120ms;
}

.opt:hover:not(:disabled) {
  border-color: oklch(70% 0.012 250);
  background: oklch(98.5% 0.006 250);
  box-shadow: 0 1px 4px oklch(0% 0 0 / 0.04);
}

.opt-key {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--ink-dim);
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  transition: all 120ms;
}

.opt.correct {
  border-color: var(--correct-bd);
  background: var(--correct-bg);
  color: var(--correct);
}
.opt.correct .opt-key {
  border-color: var(--correct-bd);
  background: var(--correct-bg);
  color: var(--correct);
}

.opt.wrong {
  border-color: var(--wrong-bd);
  background: var(--wrong-bg);
  color: var(--wrong);
}
.opt.wrong .opt-key {
  border-color: var(--wrong-bd);
  background: var(--wrong-bg);
  color: var(--wrong);
}

.opt:disabled { cursor: default; }
.opt:disabled:not(.correct):not(.wrong) { opacity: 0.35; }

/* Feedback */
.feedback {
  border-top: 1px solid var(--border);
  padding-top: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  animation: rise 280ms var(--ease-expo) both;
}

.feedback-label {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}
.feedback-label.correct { color: var(--correct); }
.feedback-label.wrong   { color: var(--wrong); }

.feedback-text {
  font-size: 0.9rem;
  color: var(--ink-mute);
  line-height: 1.76;
}

.btn-next {
  align-self: flex-start;
  background: var(--burg);
  color: oklch(98% 0.004 40);
  border: none;
  border-radius: 5px;
  padding: 0.62rem 1.25rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: opacity 130ms;
}
.btn-next:hover { opacity: 0.86; }

/* Explainer */
.btn-explain {
  align-self: flex-start;
  background: none;
  border: 1px dashed var(--border-hi);
  border-radius: 4px;
  padding: 0.55rem 0.9rem;
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--ink-dim);
  cursor: pointer;
  font-style: italic;
  transition: border-color 130ms, color 130ms;
}
.btn-explain:hover {
  border-color: var(--burg-border);
  color: var(--burg-mid);
}

.explainer {
  background: var(--parchment);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  animation: rise 240ms var(--ease-expo) both;
}

.explainer-label {
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: oklch(46% 0.13 250);
}

.explainer-text {
  font-size: 0.88rem;
  color: var(--ink-mute);
  line-height: 1.76;
}

/* ─────────────────────────────────
   DONE
───────────────────────────────── */

#done-screen {
  align-items: center;
  justify-content: center;
  background: var(--white);
}

.done-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  text-align: center;
  max-width: 400px;
  padding: 2rem;
}

.done-mark {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  border: 1px solid var(--correct-bd);
  background: var(--correct-bg);
  color: var(--correct);
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.done-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.1;
}

.done-sub {
  font-size: 0.9rem;
  color: var(--ink-mute);
  font-style: italic;
}

.done-stats {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 7px;
  overflow: hidden;
  background: var(--parchment);
}

.done-stat {
  flex: 1;
  padding: 1.1rem 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  border-right: 1px solid var(--border);
}
.done-stat:last-child { border-right: none; }

.done-stat-n {
  font-size: 2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.done-stat-l {
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-dim);
}

/* ─────────────────────────────────
   RESPONSIVE
───────────────────────────────── */

@media (max-width: 680px) {
  #home { flex-direction: column; }

  .home-left {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .home-brand { padding: 2rem 1.5rem 1.25rem; }
  .brand-name { font-size: 3.2rem; }
  .home-right { padding: 1.5rem; }

  .quiz-header { padding: 0.75rem 1.25rem; }
  .quiz-body   { padding: 1.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  .q-card, .feedback, .explainer { animation: none; }
  .quiz-progress-fill { transition: none; }
}