:root {
  --bg: #fffdfa;
  --paper: #ffffff;
  --ink: #211b16;
  --muted: #70665d;
  --line: #e8dfd4;
  --line-strong: #d7c9ba;
  --soft: #faf5ee;
  --soft-2: #f1e8dc;
  --accent: #68422c;
  --accent-strong: #3f291c;
  --green: #285c35;
  --green-bg: #f0f8ed;
  --red: #8a2c22;
  --red-bg: #fff2ef;
  --yellow-bg: #fff8df;
  --font-ui: Aptos, "Segoe UI", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, Arial, sans-serif;
  --font-text: Aptos, "Segoe UI", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-text);
  font-size: 16px;
  text-rendering: optimizeLegibility;
}
button, input, textarea, select { font: inherit; }
button { cursor: pointer; }

#app {
  width: min(860px, calc(100% - 34px));
  margin: 0 auto;
  padding: 16px 0 52px;
}

.hero {
  padding: 0 0 12px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.hero-top,
.tabs,
.button-row,
.card-meta,
.quiz-toolbar,
.filter-row,
.prompt-top,
.source-list,
.countdown-line {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.hero-top {
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 6px;
}

.eyebrow,
.kicker,
.small,
.card-meta,
.definition-group,
.source-pill,
.footer-note {
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.82rem;
}

.eyebrow {
  font-weight: 700;
  letter-spacing: 0.02em;
}

.hero h1 {
  margin: 0 0 4px;
  font-family: var(--font-ui);
  font-size: clamp(1.45rem, 3.2vw, 1.95rem);
  line-height: 1.1;
  letter-spacing: -0.035em;
  font-weight: 750;
}

.hero p {
  max-width: 620px;
  margin: 0 0 8px;
  color: #51463d;
  line-height: 1.5;
}

.countdown-line {
  margin: 6px 0 9px;
  font-family: var(--font-ui);
  color: var(--muted);
  font-size: 0.88rem;
}

.countdown-value {
  color: var(--accent-strong);
  background: #fff7eb;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 8px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.hero-main-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: start;
}

.compact-progress {
  min-width: 132px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  padding: 9px 10px;
  font-family: var(--font-ui);
  text-align: right;
}

.compact-progress strong {
  display: block;
  font-size: 1.05rem;
  line-height: 1.1;
  color: var(--accent-strong);
}

.compact-progress span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.78rem;
}

.mini-progress {
  height: 4px;
  margin-top: 8px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--soft-2);
}

.mini-progress span {
  display: block;
  height: 100%;
  margin: 0;
  background: var(--accent-strong);
}

.tabs { margin-top: 8px; }

.tab,
.btn,
.icon-btn,
.option-button,
.filter-chip {
  appearance: none;
  border: 1px solid var(--line-strong);
  background: var(--paper);
  color: var(--ink);
  border-radius: 8px;
  padding: 6px 9px;
  line-height: 1.2;
  font-family: var(--font-ui);
  font-size: 0.9rem;
  transition: background 120ms ease, border-color 120ms ease, color 120ms ease;
}

.tab:hover,
.btn:hover,
.icon-btn:hover,
.option-button:hover,
.filter-chip:hover {
  background: var(--soft);
}

.tab.active,
.filter-chip.active,
.btn-primary {
  background: var(--accent-strong);
  color: #fffaf2;
  border-color: var(--accent-strong);
  font-weight: 700;
}

.btn-danger {
  color: var(--red);
  border-color: #efb5a8;
  background: var(--red-bg);
}

.layout { display: block; }

.panel,
.card,
.quiz-card,
.definition-card,
.prompt-card,
.source-card,
.result-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.panel,
.quiz-card,
.source-card {
  padding: clamp(14px, 2.6vw, 20px);
  margin-bottom: 14px;
}

.chapter-head { margin-bottom: 12px; }

.chapter-head h2,
.panel h2,
.quiz-card h2,
.source-card h2 {
  margin: 2px 0 7px;
  font-family: var(--font-ui);
  font-size: clamp(1.16rem, 2.6vw, 1.55rem);
  letter-spacing: -0.035em;
}

.chapter-head p,
.panel p,
.card p,
.quiz-card p,
.prompt-card p,
.result-card p,
.source-card p {
  line-height: 1.6;
}

.must-know,
.example,
.trap,
.memory {
  border-radius: 10px;
  padding: 12px 13px;
  margin: 12px 0;
  line-height: 1.6;
}

.must-know,
.example,
.memory {
  background: #fff9ef;
  border: 1px solid var(--line);
}

.trap {
  background: var(--yellow-bg);
  border: 1px solid #e9c875;
}

.cards,
.glossary-grid,
.prompt-grid,
.result-grid,
.source-grid,
.checklist {
  display: grid;
  gap: 12px;
}

.cards { margin-top: 12px; }
.card,
.definition-card,
.prompt-card,
.result-card { padding: 15px; }

.card.completed {
  border-color: #a4c98f;
  background: var(--green-bg);
}

.definition-card.completed,
.prompt-card.completed,
.check-item.completed {
  border-color: #a4c98f;
  background: var(--green-bg);
}

.definition-card[data-action="toggle-concept"] {
  cursor: pointer;
  user-select: none;
}

.definition-card[data-action="toggle-concept"]:hover {
  border-color: #b99f84;
  background: var(--soft);
}

.definition-card.completed[data-action="toggle-concept"]:hover {
  border-color: #8dbc73;
  background: #eaf6e6;
}

.card h3,
.definition-card h3,
.prompt-card h3,
.result-card h3 {
  margin: 7px 0 7px;
  font-family: var(--font-ui);
  font-size: 1.05rem;
  letter-spacing: -0.015em;
}

.card ul,
.must-know ul,
.example ul,
.trap ul {
  margin: 8px 0 0;
  padding-left: 22px;
}

.card li,
.must-know li,
.example li,
.trap li {
  margin: 5px 0;
  line-height: 1.65;
}

.badge,
.done-badge,
.score-pill,
.difficulty-pill {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 8px;
  background: #fff9ef;
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.78rem;
}

.done-badge {
  color: var(--green);
  border-color: #b7d7a6;
  background: var(--green-bg);
}

.option-list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.option-button {
  width: 100%;
  text-align: left;
  border-radius: 10px;
  padding: 11px 12px;
  line-height: 1.48;
}

.option-button.correct {
  background: var(--green-bg);
  border-color: #9bc586;
  color: #244f2c;
}

.option-button.incorrect {
  background: var(--red-bg);
  border-color: #e7a092;
  color: #712019;
}


.search-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
  margin-top: 10px;
}

.search-summary {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin: 0 0 10px;
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.82rem;
}

.search-input,
.note-area {
  width: 100%;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  background: #fffdf8;
  color: var(--ink);
  padding: 10px 11px;
  font-family: var(--font-ui);
}

.search-input:focus,
.note-area:focus {
  outline: 2px solid rgba(111, 67, 40, 0.35);
  outline-offset: 2px;
}

.note-area {
  min-height: 135px;
  resize: vertical;
  line-height: 1.5;
  margin-top: 10px;
}

.filter-row { margin: 12px 0 16px; }

.definition-group {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.check-item {
  display: grid;
  grid-template-columns: 22px 1fr;
  gap: 10px;
  align-items: start;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  line-height: 1.5;
}

.check-item input { margin-top: 3px; }

.progress-shell { margin: 14px 0 16px; }
.compact-section-progress { margin-top: 0; }


.progress-meta {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-family: var(--font-ui);
  font-size: 0.84rem;
  margin-bottom: 7px;
}

.progress-bar {
  height: 5px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--soft-2);
  border: 1px solid var(--line);
}

.progress-bar span {
  display: block;
  height: 100%;
  background: var(--accent);
}

.footer-note,
.stat-grid,
.sidebar {
  display: none !important;
}

@media (max-width: 720px) {
  #app { width: min(100% - 22px, 900px); padding-top: 14px; }
  .hero-top { align-items: flex-start; }
  .hero-main-row { grid-template-columns: 1fr; }
  .compact-progress { min-width: 0; text-align: left; }
  .search-row { grid-template-columns: 1fr; }
  .tab, .btn, .filter-chip { padding: 7px 9px; }
  .panel, .quiz-card, .source-card { padding: 14px; border-radius: 10px; }
  .card, .definition-card, .prompt-card, .result-card { padding: 14px; }
}