:root {
  --bg: #0f1620;
  --bg-panel: #161f2c;
  --bg-card: #1b2532;
  --border: #2a3646;
  --text: #e7edf5;
  --text-dim: #9fb0c3;
  --accent: #ff9900;
  --accent-dark: #cc7a00;
  --green: #2ecc71;
  --red: #e74c3c;
  --blue: #4da3ff;
  --radius: 10px;
  --code-bg: #0c1119;
}

/* Warm (light, sepia-toned) theme for comfortable daytime/eye-friendly study */
:root[data-theme="warm"] {
  --bg: #faf3e7;
  --bg-panel: #fff8ee;
  --bg-card: #fdf0dd;
  --border: #e6d4b8;
  --text: #4a3b2a;
  --text-dim: #8a7355;
  --accent: #d9770f;
  --accent-dark: #b25f0a;
  --green: #2f9e56;
  --red: #c94a3a;
  --blue: #2f7bbf;
  --radius: 10px;
  --code-bg: #f1e2c6;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
  flex-wrap: wrap;
  gap: 10px;
}

.brand {
  font-weight: 700;
  font-size: 1.15rem;
}

.tabs {
  display: flex;
  gap: 6px;
}

.theme-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.85rem;
  white-space: nowrap;
}

.theme-toggle:hover { border-color: var(--accent); }

.tab-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.15s ease;
}

.tab-btn:hover { color: var(--text); border-color: var(--accent); }

.tab-btn.active {
  background: var(--accent);
  color: #1a1200;
  border-color: var(--accent);
  font-weight: 600;
}

main#app {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 16px 60px;
}

.view { display: none; }
.view.active { display: block; }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  text-align: center;
}

.stat-card .value {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-card .label {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 4px;
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 18px;
}

.panel h2 { margin-top: 0; font-size: 1.05rem; }

.cta-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
}

.btn:hover { border-color: var(--blue); }
.btn.primary { background: var(--accent); color: #1a1200; border-color: var(--accent); font-weight: 600; }
.btn.primary:hover { background: var(--accent-dark); }
.btn.danger { color: var(--red); border-color: var(--red); }
.btn.danger:hover { background: rgba(231,76,60,0.1); }
.btn.small { padding: 6px 10px; font-size: 0.8rem; }

.hint { color: var(--text-dim); font-size: 0.82rem; margin: 8px 0 0; }

.domain-list { display: flex; flex-direction: column; gap: 8px; }

.domain-row {
  display: grid;
  grid-template-columns: 1fr auto 120px;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
}

.domain-row .bar-track {
  background: #2a3646;
  border-radius: 6px;
  height: 8px;
  overflow: hidden;
}

.domain-row .bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--green), var(--accent));
}

.domain-row .pct { color: var(--text-dim); text-align: right; }

.study-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

.toolbar-actions {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.select-wrap {
  font-size: 0.85rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 6px;
}

select, input[type=text] {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
  font-size: 0.85rem;
}

.progress-text { color: var(--text-dim); font-size: 0.9rem; }

.empty-state {
  background: var(--bg-panel);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
  color: var(--text-dim);
}

.quiz-card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-dim);
  margin-bottom: 10px;
  flex-wrap: wrap;
  gap: 6px;
}

.quiz-meta .badge {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 2px 10px;
}

.quiz-meta .badge.miss-count { color: var(--red); border-color: var(--red); }

.question-html { font-size: 1.02rem; line-height: 1.5; margin-bottom: 14px; }
.question-html p { margin: 0 0 10px; }
.question-html code {
  background: var(--code-bg);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 0.9em;
}

.select-hint {
  color: var(--accent);
  font-size: 0.82rem;
  margin-bottom: 10px;
  font-weight: 600;
}

.answers { display: flex; flex-direction: column; gap: 8px; margin-bottom: 16px; }

.answer-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
  font-size: 0.92rem;
  line-height: 1.4;
}

.answer-option:hover { border-color: var(--blue); }
.answer-option .marker {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 2px solid var(--text-dim);
  margin-top: 2px;
}

.answer-option.checked .marker { background: var(--blue); border-color: var(--blue); }

.answer-option.reveal.correct { border-color: var(--green); background: rgba(46,204,113,0.08); }
.answer-option.reveal.correct .marker { background: var(--green); border-color: var(--green); }
.answer-option.reveal.wrong-pick { border-color: var(--red); background: rgba(231,76,60,0.08); }
.answer-option.reveal.wrong-pick .marker { background: var(--red); border-color: var(--red); }
.answer-option.disabled { cursor: default; }

.quiz-actions { display: flex; gap: 10px; margin-bottom: 12px; }

.result-banner {
  padding: 10px 14px;
  border-radius: 8px;
  font-weight: 600;
  margin-bottom: 14px;
}
.result-banner.correct { background: rgba(46,204,113,0.15); color: var(--green); }
.result-banner.incorrect { background: rgba(231,76,60,0.15); color: var(--red); }

.explanation {
  background: var(--bg-card);
  border-left: 3px solid var(--accent);
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 0.9rem;
  line-height: 1.5;
}
.explanation p { margin: 0 0 8px; }
.explanation code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }
.explanation a { color: var(--blue); }

.question-list { display: flex; flex-direction: column; gap: 10px; }

.question-list-item {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  cursor: pointer;
}
.question-list-item:hover { border-color: var(--blue); }
.question-list-item .qli-top {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 6px;
}
.question-list-item .qli-text { font-size: 0.92rem; }
.question-list-item .qli-badge {
  border-radius: 999px;
  padding: 1px 9px;
  font-size: 0.7rem;
}
.qli-badge.wrong { background: rgba(231,76,60,0.15); color: var(--red); }
.qli-badge.correct { background: rgba(46,204,113,0.15); color: var(--green); }
.qli-badge.unseen { background: rgba(255,153,0,0.15); color: var(--accent); }

.browse-toolbar {
  display: flex;
  gap: 10px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.browse-toolbar input { flex: 1; min-width: 200px; }