@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,500;0,700;0,900;1,400;1,700&family=Barlow:ital,wght@0,300;0,400;0,500;0,600;0,700;1,300;1,400&display=swap');

/* ── Tokens ─────────────────────────────────────────────── */
:root {
  --paper:        #F5EDD8;
  --paper-dark:   #EDE3C8;
  --ink:          #14100A;
  --ink-mid:      #4A3F30;
  --ink-light:    #8A7A60;
  --rule:         #D4C8A8;
  --accent:       #C41E2A;
  --accent-pale:  #F5E0E1;
  --white:        #FDFAF4;

  --font-display: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-body:    'Barlow', 'Helvetica Neue', Arial, sans-serif;

  --nav-h: 52px;
  --max-w: 1240px;

  --ease-sharp: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* ── Typography ─────────────────────────────────────────── */
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.15; }
p { text-wrap: pretty; }

.display-xl {
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 96px);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.02em;
}

.display-lg {
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 700;
  line-height: 1.05;
}

.label {
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
}

.num-feature {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-weight: 900;
  color: var(--accent);
}

/* ── Nav ────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--paper);
  border-bottom: 2px solid var(--ink);
  height: var(--nav-h);
  display: flex;
  align-items: stretch;
}

.nav-inner {
  max-width: var(--max-w);
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-masthead {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-right: 32px;
  flex-shrink: 0;
}

.nav-course {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
  white-space: nowrap;
}

.nav-rule {
  width: 1px;
  height: 18px;
  background: var(--rule);
  align-self: center;
  margin: 0 16px;
}

.nav-links {
  display: flex;
  align-items: stretch;
  gap: 0;
  flex: 1;
  overflow-x: auto;
}

.nav-link {
  display: flex;
  align-items: center;
  padding: 0 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-light);
  cursor: pointer;
  border: none;
  background: none;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  transition: color 0.15s, border-color 0.15s;
  white-space: nowrap;
  text-decoration: none;
}

.nav-link:hover { color: var(--ink); }
.nav-link.active { color: var(--accent); border-bottom-color: var(--accent); }

.nav-search-btn {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--rule);
  background: var(--white);
  color: var(--ink-light);
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
  flex-shrink: 0;
}
.nav-search-btn:hover { border-color: var(--ink-mid); color: var(--ink); }
.nav-search-kbd {
  font-size: 10px;
  background: var(--paper-dark);
  padding: 1px 5px;
  border-radius: 2px;
  font-family: var(--font-body);
}

/* ── Module header ──────────────────────────────────────── */
.module-header {
  border-bottom: 1px solid var(--rule);
  padding: 40px 24px 32px;
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
}

.module-header-left { flex: 1; }

.module-issue-num {
  font-family: var(--font-display);
  font-size: 80px;
  font-weight: 900;
  line-height: 1;
  color: var(--accent);
  opacity: 0.18;
  position: absolute;
  right: 24px;
  top: 0;
  pointer-events: none;
  user-select: none;
}

.module-title {
  font-family: var(--font-display);
  font-size: 36px;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 6px;
}

.module-subtitle {
  font-size: 14px;
  color: var(--ink-mid);
  font-style: italic;
}

/* ── Content wrapper ────────────────────────────────────── */
.content-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* ── Tag chips ──────────────────────────────────────────── */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 8px;
  border: 1px solid var(--rule);
  color: var(--ink-light);
  cursor: pointer;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
  background: transparent;
  font-family: var(--font-body);
  white-space: nowrap;
}
.tag:hover { border-color: var(--ink-mid); color: var(--ink); }
.tag.active { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.tag.accent-tag { border-color: var(--accent); color: var(--accent); }

/* ── Search bar ─────────────────────────────────────────── */
.search-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 2px solid var(--ink);
  padding: 10px 0;
  margin-bottom: 24px;
}

.search-bar input {
  flex: 1;
  border: none;
  background: transparent;
  font-family: var(--font-body);
  font-size: 15px;
  color: var(--ink);
  outline: none;
}
.search-bar input::placeholder { color: var(--ink-light); }

.search-icon { color: var(--ink-light); flex-shrink: 0; }

/* ── Glossary layout ────────────────────────────────────── */
.glossary-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 0;
  min-height: calc(100vh - var(--nav-h) - 180px);
  max-width: var(--max-w);
  margin: 0 auto;
}

.glossary-list {
  border-right: 1px solid var(--rule);
  overflow-y: auto;
  max-height: calc(100vh - var(--nav-h) - 180px);
  position: sticky;
  top: calc(var(--nav-h) + 180px);
}

.glossary-list-item {
  padding: 12px 16px;
  border-bottom: 1px solid var(--rule);
  cursor: pointer;
  transition: background 0.1s;
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.glossary-list-item:hover { background: var(--paper-dark); }
.glossary-list-item.selected { background: var(--ink); color: var(--paper); }
.glossary-list-item.selected .item-term { color: var(--paper); }
.glossary-list-item.selected .item-type { color: var(--paper); opacity: 0.6; }

.item-term {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.3;
}
.item-type {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-light);
}

.glossary-detail {
  padding: 32px 40px;
  overflow-y: auto;
  max-height: calc(100vh - var(--nav-h) - 180px);
}

.glossary-detail-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 300px;
  color: var(--ink-light);
  font-style: italic;
  font-size: 15px;
}

.detail-type-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}

.detail-term {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 16px;
}

.detail-definition {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-mid);
  margin-bottom: 20px;
  max-width: 620px;
}

.detail-summary {
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink-mid);
  font-style: italic;
  border-left: 3px solid var(--accent);
  padding-left: 16px;
  margin-bottom: 24px;
}

.detail-walkthrough {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
  max-width: 660px;
}

.detail-walkthrough p {
  margin-bottom: 14px;
}

.detail-walkthrough strong {
  font-weight: 600;
  color: var(--ink);
}

.detail-rule {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 24px 0;
}

.related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.related-chip {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 10px;
  border: 1px solid var(--rule);
  color: var(--ink-mid);
  cursor: pointer;
  background: none;
  font-family: var(--font-body);
  transition: all 0.12s;
}
.related-chip:hover { border-color: var(--accent); color: var(--accent); }

.flashcard-back-box {
  background: var(--paper-dark);
  border-left: 3px solid var(--ink);
  padding: 12px 16px;
  margin-top: 20px;
  font-size: 13px;
  color: var(--ink-mid);
  max-width: 560px;
}
.flashcard-back-label {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 4px;
}

/* ── Topics ─────────────────────────────────────────────── */
.topics-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  min-height: calc(100vh - var(--nav-h) - 180px);
  max-width: var(--max-w);
  margin: 0 auto;
}

.topics-sidebar {
  border-right: 1px solid var(--rule);
  position: sticky;
  top: calc(var(--nav-h) + 180px);
  max-height: calc(100vh - var(--nav-h) - 180px);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.topics-list-item {
  padding: 14px 16px;
  border: none;
  border-bottom: 1px solid var(--rule);
  background: transparent;
  text-align: left;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: var(--font-body);
  transition: background 0.1s;
}
.topics-list-item:hover { background: var(--paper-dark); }
.topics-list-item.selected { background: var(--ink); }
.topics-list-item.selected .item-term { color: var(--paper); }
.topics-list-item.selected .item-type { color: var(--paper); opacity: 0.6; }

.topics-detail {
  padding: 28px 40px 60px;
  overflow-y: auto;
  max-height: calc(100vh - var(--nav-h) - 180px);
}

.topic-exam-weight {
  background: var(--paper-dark);
  padding: 12px 16px;
  border-left: 3px solid var(--accent);
  margin: 16px 0 28px;
  max-width: 720px;
}
.topic-exam-weight .label { color: var(--accent); }
.topic-exam-weight p {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-mid);
  margin-top: 4px;
}

.topic-sections { max-width: 880px; }
.topic-section {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--rule);
}
.topic-section:last-child { border-bottom: none; }

.topic-section-h {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--ink);
}

.topic-section-body {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
}
.topic-section-body p { margin-bottom: 12px; }
.topic-section-body strong { color: var(--ink); font-weight: 600; }
.topic-section-body code {
  font-family: 'SF Mono', 'Fira Mono', monospace;
  font-size: 12.5px;
  background: var(--paper-dark);
  padding: 1px 5px;
}

.md-list {
  margin: 0 0 12px 22px;
  padding: 0;
}
.md-list li {
  margin-bottom: 6px;
  line-height: 1.7;
}

.md-table {
  width: 100%;
  border-collapse: collapse;
  margin: 8px 0 16px;
  font-size: 13px;
}
.md-table th, .md-table td {
  border-bottom: 1px solid var(--rule);
  padding: 8px 12px;
  text-align: left;
  vertical-align: top;
}
.md-table th {
  background: var(--paper-dark);
  font-weight: 600;
  font-size: 11px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.topic-keyterms, .topic-readings, .topic-examquestions {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
  max-width: 880px;
}

.topic-readings-list {
  list-style: none;
  margin: 8px 0 0 0;
  padding: 0;
}
.topic-readings-list li {
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-mid);
  margin-bottom: 4px;
}
.topic-readings-list li.supp { opacity: 0.7; }
.reading-author { font-weight: 600; color: var(--ink); }
.reading-year { color: var(--ink-light); }
.reading-title { color: var(--ink-mid); font-style: italic; }
.reading-supp { font-size: 10px; color: var(--accent); margin-left: 6px; }

.topic-examquestions-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}
.topic-examquestion-chip {
  font-size: 12px;
  padding: 5px 10px;
  border: 1px solid var(--rule);
  background: var(--white);
  color: var(--ink-mid);
  cursor: pointer;
  font-family: var(--font-body);
  transition: all 0.12s;
  text-align: left;
}
.topic-examquestion-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.topic-examquestion-chip strong { color: var(--ink); font-size: 11px; }

/* ── Timeline ───────────────────────────────────────────── */
.timeline-wrap {
  padding: 40px 24px 80px;
  max-width: var(--max-w);
  margin: 0 auto;
}

.timeline-era {
  margin-bottom: 56px;
}

.timeline-era-header {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--ink);
}

.timeline-era-year {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
}

.timeline-era-name {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--ink-mid);
}

.timeline-events {
  display: grid;
  gap: 0;
  padding-left: 24px;
  border-left: 2px solid var(--rule);
}

.timeline-event {
  position: relative;
  padding: 20px 0 20px 28px;
  border-bottom: 1px solid var(--rule);
}
.timeline-event:last-child { border-bottom: none; }

.timeline-event::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 26px;
  width: 12px;
  height: 12px;
  background: var(--paper);
  border: 2px solid var(--ink);
}

.timeline-event.highlight::before {
  background: var(--accent);
  border-color: var(--accent);
}

.event-date {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 4px;
}

.event-title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 6px;
}

.event-summary {
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-mid);
  max-width: 640px;
}

.event-related {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 10px;
}

/* ── Flashcards ─────────────────────────────────────────── */

.fc-mode-toggle {
  display: inline-flex;
  border: 1.5px solid var(--ink);
  margin-bottom: 24px;
}

.fc-mode-btn {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 7px 18px;
  border: none;
  background: transparent;
  color: var(--ink-light);
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}
.fc-mode-btn + .fc-mode-btn { border-left: 1.5px solid var(--ink); }
.fc-mode-btn.active { background: var(--ink); color: var(--paper); }

.fc-sr-dashboard {
  display: flex;
  align-items: center;
  gap: 28px;
  padding: 14px 20px;
  background: var(--paper-dark);
  border: 1px solid var(--rule);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.fc-sr-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  min-width: 56px;
}

.fc-sr-num {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 900;
  line-height: 1;
}
.fc-sr-stat.overdue .fc-sr-num { color: var(--accent); }
.fc-sr-stat.new     .fc-sr-num { color: var(--ink); }
.fc-sr-stat.mastered .fc-sr-num { color: #2E7D32; }

.fc-sr-label {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-light);
  white-space: nowrap;
}

.fc-reset-btn {
  margin-left: auto;
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-light);
  background: none;
  border: 1px solid var(--rule);
  padding: 5px 10px;
  cursor: pointer;
  transition: color 0.12s, border-color 0.12s;
}
.fc-reset-btn:hover { color: var(--accent); border-color: var(--accent); }

.fc-rating-row {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  animation: ratingReveal 0.18s ease;
}

@keyframes ratingReveal {
  from { opacity: 0; transform: translateY(5px); }
  to   { opacity: 1; transform: translateY(0); }
}

.fc-rating-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px 6px;
  border: 1.5px solid var(--rule);
  background: var(--white);
  cursor: pointer;
  font-family: var(--font-body);
  transition: border-color 0.12s, background 0.12s;
}
.fc-rating-btn.hard:hover { border-color: var(--accent); background: var(--accent-pale); }
.fc-rating-btn.good:hover { border-color: var(--ink);    background: var(--paper-dark); }
.fc-rating-btn.easy:hover { border-color: #2E7D32;       background: #E8F5E9; }

.fc-rating-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
}
.fc-rating-btn.hard .fc-rating-label { color: var(--accent); }
.fc-rating-btn.easy .fc-rating-label { color: #2E7D32; }

.fc-rating-sub {
  font-size: 10px;
  color: var(--ink-light);
}

.fc-btn-flip {
  flex: 1;
}

.flashcards-wrap {
  max-width: 780px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.fc-controls-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
  flex-wrap: wrap;
  gap: 16px;
}

.fc-progress {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
}

.fc-progress span { color: var(--ink-light); font-size: 18px; }

.fc-stats {
  display: flex;
  gap: 16px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.fc-stat-got { color: #2E7D32; }
.fc-stat-review { color: var(--accent); }

.fc-card-wrap {
  perspective: 1200px;
  height: 320px;
  margin-bottom: 28px;
  cursor: pointer;
}

.fc-card {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.45s var(--ease-sharp);
}

.fc-card.flipped { transform: rotateY(180deg); }

.fc-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border: 2px solid var(--ink);
  background: var(--white);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px;
  text-align: center;
}

.fc-face-back {
  transform: rotateY(180deg);
  background: var(--paper-dark);
}

.fc-face-label {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 16px;
  align-self: flex-start;
}

.fc-front-text {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--ink);
}

.fc-back-text {
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  max-width: 500px;
}

.fc-flip-hint {
  position: absolute;
  bottom: 14px;
  right: 16px;
  font-size: 10px;
  color: var(--ink-light);
  letter-spacing: 0.04em;
}

.fc-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-bottom: 24px;
}

.fc-btn {
  padding: 12px 28px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}

.fc-btn:hover { background: var(--ink); color: var(--paper); }

.fc-btn-got { border-color: #2E7D32; color: #2E7D32; }
.fc-btn-got:hover { background: #2E7D32; color: var(--white); }

.fc-btn-review { border-color: var(--accent); color: var(--accent); }
.fc-btn-review:hover { background: var(--accent); color: var(--white); }

.fc-btn-nav { border-color: var(--rule); color: var(--ink-light); }
.fc-btn-nav:hover { background: var(--paper-dark); color: var(--ink); border-color: var(--ink); }

.fc-shortcuts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  font-size: 11px;
  color: var(--ink-light);
}
.fc-shortcuts kbd {
  background: var(--paper-dark);
  border: 1px solid var(--rule);
  padding: 1px 6px;
  font-size: 10px;
  font-family: var(--font-body);
  border-radius: 2px;
}

.fc-deck-done {
  text-align: center;
  padding: 60px 20px;
}
.fc-deck-done h2 {
  font-family: var(--font-display);
  font-size: 32px;
  margin-bottom: 12px;
}
.fc-deck-done p { color: var(--ink-mid); margin-bottom: 24px; }

/* ── Quiz ───────────────────────────────────────────────── */
.quiz-wrap {
  max-width: 820px;
  margin: 0 auto;
  padding: 28px 24px 80px;
}

.quiz-controls {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 16px;
}

.quiz-mode-btn {
  padding: 6px 14px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  background: transparent;
  color: var(--ink-light);
  font-family: var(--font-body);
}
.quiz-mode-btn.active { background: var(--ink); color: var(--paper); }

.quiz-scorebar {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 16px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--rule);
  margin-bottom: 24px;
}

.quiz-card {
  border: 1px solid var(--rule);
  background: var(--white);
  padding: 18px 20px;
  margin-bottom: 14px;
  transition: border-color 0.15s, background 0.15s;
}
.quiz-card.correct { border-color: #2E7D32; background: #F0F7F0; }
.quiz-card.incorrect { border-color: var(--accent); background: var(--accent-pale); }

.quiz-card-head {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 14px;
}

.quiz-num {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 900;
  color: var(--accent);
  min-width: 32px;
  line-height: 1;
}
.quiz-prompt {
  flex: 1;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink);
}
.quiz-topic {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-light);
  white-space: nowrap;
  padding: 2px 6px;
  border: 1px solid var(--rule);
  align-self: flex-start;
}

.quiz-options { display: flex; gap: 8px; flex-wrap: wrap; }
.quiz-options-mc { display: flex; flex-direction: column; gap: 6px; }

.quiz-option-btn {
  padding: 9px 14px;
  border: 1px solid var(--rule);
  background: var(--white);
  color: var(--ink);
  font-size: 13px;
  font-family: var(--font-body);
  cursor: pointer;
  text-align: left;
  transition: all 0.12s;
  display: flex;
  align-items: center;
  gap: 10px;
}
.quiz-option-btn.mc { padding: 10px 14px; line-height: 1.5; }
.quiz-option-btn:hover:not(:disabled) { border-color: var(--ink); }
.quiz-option-btn:disabled { cursor: default; }
.quiz-option-btn.selected { border-color: var(--ink); background: var(--paper-dark); }
.quiz-option-btn.correct { border-color: #2E7D32; background: #E8F5E9; color: #1B5E20; }
.quiz-option-btn.incorrect { border-color: var(--accent); background: var(--accent-pale); color: var(--accent); }

.quiz-mc-letter {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 11px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--paper-dark);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.quiz-option-btn.correct .quiz-mc-letter { background: #2E7D32; color: white; }
.quiz-option-btn.incorrect .quiz-mc-letter { background: var(--accent); color: white; }

.quiz-explanation {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--rule);
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-mid);
}
.quiz-explanation .label { color: var(--ink); margin-bottom: 4px; display: block; }

/* ── Exams ──────────────────────────────────────────────── */
.exams-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.exam-paper-group {
  margin-bottom: 48px;
}

.exam-paper-header {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--ink);
  margin-bottom: 0;
}

.exam-paper-label {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
}

.exam-paper-meta {
  font-size: 12px;
  color: var(--ink-light);
  font-style: italic;
}

.exam-question {
  border-bottom: 1px solid var(--rule);
}

.exam-question.reconstructed { background: rgba(196, 30, 42, 0.025); }

.exam-reconstructed-banner {
  background: var(--paper-dark);
  border-left: 3px solid var(--accent);
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-mid);
  margin-bottom: 8px;
}
.exam-reconstructed-banner strong { color: var(--accent); }

.exam-q-reconstructed-badge {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-pale);
  padding: 2px 6px;
  flex-shrink: 0;
  white-space: nowrap;
}

.exam-q-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 0;
  cursor: pointer;
  user-select: none;
  transition: opacity 0.12s;
}
.exam-q-header:hover { opacity: 0.75; }

.exam-q-num {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  color: var(--accent);
  min-width: 40px;
  line-height: 1;
}

.exam-q-prompt {
  flex: 1;
  font-size: 14px;
  line-height: 1.5;
  color: var(--ink);
}

.exam-q-points {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink-light);
  white-space: nowrap;
}

.exam-q-chevron {
  color: var(--ink-light);
  transition: transform 0.2s var(--ease-sharp);
  flex-shrink: 0;
}
.exam-q-chevron.open { transform: rotate(90deg); }

.exam-q-body {
  overflow: hidden;
  transition: max-height 0.3s var(--ease-sharp), opacity 0.25s;
}
.exam-q-body.closed { max-height: 0; opacity: 0; }
.exam-q-body.open { max-height: 2000px; opacity: 1; }

.exam-q-answer {
  padding: 0 0 24px 56px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 680px;
}

.exam-q-answer p { margin-bottom: 10px; }

.exam-placeholder-msg {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  text-align: center;
  gap: 12px;
  border: 2px dashed var(--rule);
  margin-top: 16px;
}

.exam-placeholder-msg h3 {
  font-family: var(--font-display);
  font-size: 22px;
  color: var(--ink-mid);
}
.exam-placeholder-msg p { font-size: 14px; color: var(--ink-light); max-width: 480px; }
.exam-placeholder-msg code {
  font-size: 12px;
  background: var(--paper-dark);
  padding: 2px 6px;
  font-family: 'SF Mono', 'Fira Mono', monospace;
}

/* ── Mock exam ──────────────────────────────────────────── */
.mock-wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 28px 24px 80px;
}

.mock-setup {
  padding: 16px 0 40px;
}

.mock-paper-list {
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr;
  margin-bottom: 24px;
}

.mock-paper-card {
  border: 1px solid var(--rule);
  background: var(--white);
  padding: 14px 18px;
  cursor: pointer;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: var(--font-body);
  transition: all 0.12s;
}
.mock-paper-card:hover { border-color: var(--ink); }
.mock-paper-card.selected { border-color: var(--accent); background: var(--accent-pale); }
.mock-paper-card strong { font-size: 14px; color: var(--ink); }

.mock-grading-ref {
  margin-top: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
}
.mock-grade-pill {
  font-size: 11px;
  padding: 4px 10px;
  border: 1px solid var(--rule);
  color: var(--ink-light);
  font-family: var(--font-body);
}

.mock-timer-bar {
  position: sticky;
  top: var(--nav-h);
  z-index: 50;
  background: var(--paper);
  border-bottom: 2px solid var(--ink);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 0 -24px 24px;
  flex-wrap: wrap;
}
.mock-timer-bar.low { background: #FFF8E1; }
.mock-timer-bar.critical { background: var(--accent-pale); }

.mock-timer-display {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 900;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}
.mock-timer-bar.critical .mock-timer-display { color: var(--accent); }

.mock-review-bar {
  border: 2px solid var(--ink);
  background: var(--paper-dark);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.mock-questions { }

.mock-question {
  border: 1px solid var(--rule);
  background: var(--white);
  padding: 18px 20px;
  margin-bottom: 18px;
}
.mock-question.reviewed { background: var(--paper-dark); }

.mock-q-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.mock-answer-input {
  width: 100%;
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.6;
  border: 1px solid var(--rule);
  background: var(--paper);
  padding: 12px 14px;
  resize: vertical;
  outline: none;
  color: var(--ink);
  transition: border-color 0.12s;
}
.mock-answer-input:focus { border-color: var(--ink); }

.mock-your-answer {
  margin: 12px 0 18px;
  padding: 10px 14px;
  background: var(--white);
  border-left: 3px solid var(--ink);
}
.mock-your-answer.empty { color: var(--ink-light); font-style: italic; padding: 8px 14px; }
.mock-your-answer pre {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink);
  white-space: pre-wrap;
  margin-top: 4px;
}

.mock-model-answer {
  padding: 12px 14px;
  border-left: 3px solid var(--accent);
  background: var(--white);
}
.mock-model-answer .topic-section-body { font-size: 13.5px; }

/* ── Search palette ─────────────────────────────────────── */
.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(20, 16, 10, 0.6);
  z-index: 200;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 100px;
  animation: fadeIn 0.15s ease;
}

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.search-palette {
  width: 100%;
  max-width: 600px;
  background: var(--white);
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 var(--ink);
  overflow: hidden;
  animation: slideDown 0.18s var(--ease-sharp);
}

@keyframes slideDown {
  from { transform: translateY(-12px); opacity: 0; }
  to   { transform: translateY(0);     opacity: 1; }
}

.sp-input-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--rule);
}

.sp-input {
  flex: 1;
  border: none;
  background: transparent;
  font-family: var(--font-body);
  font-size: 16px;
  color: var(--ink);
  outline: none;
}
.sp-input::placeholder { color: var(--ink-light); }

.sp-results {
  max-height: 400px;
  overflow-y: auto;
}

.sp-section-label {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-light);
  padding: 12px 20px 4px;
  background: var(--paper-dark);
}

.sp-result {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 20px;
  cursor: pointer;
  border-bottom: 1px solid var(--rule);
  transition: background 0.1s;
}
.sp-result:last-child { border-bottom: none; }
.sp-result:hover, .sp-result.highlighted { background: var(--paper-dark); }

.sp-result-term {
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  flex: 0 0 auto;
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sp-result-snippet {
  font-size: 12px;
  color: var(--ink-light);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}

.sp-empty {
  padding: 32px 20px;
  text-align: center;
  font-size: 14px;
  color: var(--ink-light);
  font-style: italic;
}

.sp-results-meta {
  padding: 8px 18px 6px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-light);
  font-family: var(--font-body);
  border-bottom: 1px dashed var(--rule);
}

/* Highlighted match within search-palette result text */
.sp-result mark,
.sp-result-term mark,
.sp-result-snippet mark {
  background: var(--accent-pale);
  color: var(--accent);
  padding: 0 2px;
  border-radius: 1px;
  font-weight: 600;
}
.sp-result.highlighted mark,
.sp-result:hover mark {
  background: var(--accent);
  color: var(--paper);
}

/* ── Filter bar ─────────────────────────────────────────── */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 0;
}

/* ── Misc utilities ─────────────────────────────────────── */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 60vh;
  font-family: var(--font-display);
  font-size: 20px;
  color: var(--ink-light);
  font-style: italic;
}

.empty-state {
  padding: 48px 24px;
  text-align: center;
  color: var(--ink-light);
  font-style: italic;
}

.section-rule {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 32px 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

/* ── Active Recall ──────────────────────────────────────── */
.recall-section {
  margin-top: 4px;
}

.recall-label {
  margin-bottom: 14px;
}

.recall-item {
  padding: 14px 0;
  border-top: 1px solid var(--rule);
}
.recall-item:last-child { border-bottom: 1px solid var(--rule); }

.recall-question-text {
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink);
  margin-bottom: 10px;
  max-width: 600px;
}

.recall-reveal-btn {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-light);
  background: none;
  border: 1px solid var(--rule);
  padding: 4px 10px;
  cursor: pointer;
  transition: border-color 0.12s, color 0.12s;
}
.recall-reveal-btn:hover { border-color: var(--ink-mid); color: var(--ink); }
.recall-reveal-btn.revealed { border-color: var(--ink); color: var(--ink); }

.recall-answer {
  margin-top: 10px;
  padding: 10px 14px;
  background: var(--paper-dark);
  border-left: 3px solid var(--ink);
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-mid);
  max-width: 580px;
  animation: recallFadeIn 0.18s ease;
}

@keyframes recallFadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 1100px) {
  .nav-link { padding: 0 11px; font-size: 11px; }
}

@media (max-width: 920px) {
  .topics-layout { grid-template-columns: 220px 1fr; }
  .topics-detail { padding: 24px 24px 60px; }
}

@media (max-width: 768px) {
  .glossary-layout {
    grid-template-columns: 1fr;
  }

  .glossary-list {
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 2px solid var(--ink);
  }

  .glossary-detail {
    padding: 24px 0;
    max-height: none;
  }

  .topics-layout {
    grid-template-columns: 1fr;
  }
  .topics-sidebar {
    position: static;
    max-height: none;
    border-right: none;
    border-bottom: 2px solid var(--ink);
    flex-direction: row;
    overflow-x: auto;
  }
  .topics-list-item {
    border-bottom: none;
    border-right: 1px solid var(--rule);
    min-width: 200px;
  }
  .topics-detail {
    padding: 24px 0;
    max-height: none;
  }

  .module-header { flex-direction: column; align-items: flex-start; }

  .fc-card-wrap { height: 260px; }

  .nav-links {
    gap: 0;
    overflow-x: auto;
    flex: 1 1 auto;
    min-width: 0;
  }
  .nav-link { padding: 0 8px; font-size: 10px; flex-shrink: 0; }

  .timeline-era-year { font-size: 40px; }

  .search-overlay { padding-top: 60px; align-items: flex-start; }

  .quiz-controls { flex-direction: column; align-items: flex-start; }
  .mock-timer-bar { gap: 8px; padding: 10px 14px; }
  .mock-timer-display { font-size: 24px; }
}

@media (max-width: 480px) {
  .nav-course { display: none; }
  .nav-rule { display: none; }
  .nav-masthead .label { display: none; }
  .fc-actions { flex-wrap: wrap; }
  .nav-search-btn { padding: 5px 8px; font-size: 10px; }
  .nav-search-btn span:not(.nav-search-kbd) { display: none; }
}

/* ── Print (exams only) ─────────────────────────────────── */
@media print {
  .nav, .nav-search-btn, .search-overlay,
  .module-header, .filter-bar, .tags,
  .exam-q-chevron, .fc-shortcuts,
  .fc-controls-top, .fc-actions { display: none !important; }

  body { background: white; color: black; font-size: 12pt; }

  .exams-wrap { padding: 0; max-width: 100%; }

  .exam-q-body.closed {
    max-height: none !important;
    opacity: 1 !important;
  }

  .exam-q-header { break-inside: avoid; }

  .exam-q-answer {
    padding-left: 0;
    color: black;
  }

  .exam-paper-header {
    page-break-before: always;
    break-before: page;
  }
  .exam-paper-header:first-child {
    page-break-before: avoid;
    break-before: avoid;
  }
}

/* ── Mind-map ───────────────────────────────────────────── */
.mindmap-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 24px 24px 48px;
}

.mindmap-toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.mindmap-search {
  position: relative;
  display: flex;
  align-items: center;
  flex: 0 1 320px;
  background: var(--white);
  border: 1.5px solid var(--ink);
  height: 38px;
  padding: 0 10px;
  gap: 8px;
}
.mindmap-search-icon { color: var(--ink-light); display: flex; }
.mindmap-search input {
  flex: 1;
  border: none;
  background: transparent;
  outline: none;
  font: 500 13px var(--font-body);
  color: var(--ink);
  letter-spacing: 0.01em;
}
.mindmap-search input::placeholder { color: var(--ink-light); }
.mindmap-search-clear {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--ink-light);
  font-size: 18px;
  line-height: 1;
  padding: 0 4px;
}

.mindmap-zoom {
  display: flex;
  border: 1.5px solid var(--ink);
  background: var(--white);
  height: 38px;
}
.mindmap-zoom button {
  width: 38px;
  height: 36px;
  background: transparent;
  border: none;
  border-right: 1px solid var(--rule);
  cursor: pointer;
  font: 700 16px var(--font-body);
  color: var(--ink);
  transition: background-color 160ms var(--ease-sharp);
}
.mindmap-zoom button:last-child { border-right: none; }
.mindmap-zoom button:hover { background: var(--paper-dark); }

.mindmap-legend {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  font: 500 11px var(--font-body);
  color: var(--ink-mid);
  letter-spacing: 0.02em;
}
.mindmap-legend-marker {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid #c89b3d;
  box-shadow: 0 0 8px rgba(200, 155, 61, 0.55);
  display: inline-block;
}

/* Stage / canvas */
.mindmap-stage {
  position: relative;
  background: var(--white);
  border: 1.5px solid var(--ink);
  height: clamp(560px, 72vh, 820px);
  overflow: hidden;
  /* faint dot grid + radial wash */
  background-image:
    radial-gradient(circle at center,
      rgba(245, 224, 225, 0.35) 0%,
      rgba(253, 250, 244, 0) 60%),
    radial-gradient(rgba(20, 16, 10, 0.05) 1px, transparent 1.4px);
  background-size: 100% 100%, 22px 22px;
  background-position: center, 0 0;
}

.mindmap-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.mindmap-loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font: 500 13px var(--font-body);
  color: var(--ink-light);
  pointer-events: none;
}

/* Popup card */
.mindmap-popup {
  position: absolute;
  width: 360px;
  max-width: calc(100vw - 32px);
  background: var(--paper);
  border: 1.5px solid var(--ink);
  border-top: 4px solid var(--cluster-accent, var(--accent));
  padding: 20px 22px 18px;
  box-shadow: 8px 10px 0 rgba(20, 16, 10, 0.08), 0 2px 18px rgba(20, 16, 10, 0.12);
  z-index: 10;
  animation: popupIn 220ms var(--ease-sharp);
  font-family: var(--font-body);
}
@keyframes popupIn {
  from { opacity: 0; transform: translateY(6px) scale(0.98); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.mindmap-popup-close {
  position: absolute;
  top: 8px;
  right: 8px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--ink-light);
  font-size: 22px;
  line-height: 1;
  padding: 4px 10px;
  font-weight: 300;
}
.mindmap-popup-close:hover { color: var(--ink); }

.mindmap-popup-cluster {
  display: flex;
  align-items: center;
  gap: 8px;
  font: 700 9px var(--font-body);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-light);
  margin-bottom: 8px;
}
.mindmap-popup-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cluster-accent, var(--accent));
}

.mindmap-popup-term {
  font: 700 22px/1.2 var(--font-display);
  color: var(--ink);
  margin: 0 0 12px 0;
  letter-spacing: -0.01em;
}

.mindmap-popup-def {
  font: 400 13.5px/1.55 var(--font-body);
  color: var(--ink-mid);
  margin: 0 0 14px 0;
}
.mindmap-popup-def-empty { font-style: italic; color: var(--ink-light); }

.mindmap-popup-freq {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  background: rgba(200, 155, 61, 0.10);
  border-left: 2px solid #c89b3d;
  padding: 8px 10px;
  margin-bottom: 14px;
  font: 500 11px/1.5 var(--font-body);
  color: var(--ink-mid);
  letter-spacing: 0.01em;
}
.mindmap-popup-freq-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #c89b3d;
  box-shadow: 0 0 6px rgba(200, 155, 61, 0.6);
  margin-top: 4px;
  flex-shrink: 0;
}

.mindmap-popup-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--ink);
  color: var(--paper);
  border: none;
  padding: 9px 14px;
  font: 600 11px var(--font-body);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background-color 180ms var(--ease-sharp);
}
.mindmap-popup-link:hover { background: var(--accent); }

.mindmap-hint {
  margin-top: 12px;
  text-align: center;
  font: 500 11px var(--font-body);
  color: var(--ink-light);
  letter-spacing: 0.04em;
}

/* Mobile */
@media (max-width: 640px) {
  .mindmap-wrap { padding: 16px 12px 32px; }
  .mindmap-toolbar { gap: 10px; }
  .mindmap-search { flex: 1 1 100%; }
  .mindmap-zoom { order: 2; }
  .mindmap-legend { order: 3; margin-left: 0; }
  .mindmap-stage { height: 64vh; }
  .mindmap-popup {
    position: fixed;
    left: 8px;
    right: 8px;
    bottom: 8px;
    top: auto;
    width: auto;
    max-width: none;
    transform: none !important;
  }
  @keyframes popupIn {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
  }
}

/* ── Practice Calculations ──────────────────────────────── */
.calc-wrap {
  max-width: 860px;
  margin: 0 auto;
  padding: 28px 24px 80px;
}

.calc-controls {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 16px;
}

.calc-diff-btn {
  padding: 6px 14px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  background: transparent;
  color: var(--ink-light);
  font-family: var(--font-body);
}
.calc-diff-btn + .calc-diff-btn { border-left: 1px solid var(--rule); }
.calc-diff-btn:hover { color: var(--ink); }
.calc-diff-btn.active { background: var(--ink); color: var(--paper); }

.calc-bulk-btn {
  padding: 6px 12px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--ink-light);
  font-family: var(--font-body);
  cursor: pointer;
  transition: all 0.12s;
}
.calc-bulk-btn:hover { border-color: var(--ink); color: var(--ink); }

.calc-scorebar {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 16px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--rule);
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.calc-card {
  border: 1px solid var(--rule);
  background: var(--white);
  padding: 22px 24px;
  margin-bottom: 18px;
  transition: border-color 0.15s;
}
.calc-card:hover { border-color: var(--ink-mid); }
.calc-card.revealed { border-color: var(--ink); }

.calc-card-head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--rule);
}

.calc-num {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  color: var(--accent);
  min-width: 36px;
  line-height: 1;
  letter-spacing: 0.02em;
}

.calc-title {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.25;
  color: var(--ink);
  margin: 0 0 6px;
}

.calc-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 11px;
  color: var(--ink-light);
  font-family: var(--font-body);
}

.calc-cat-pill {
  padding: 2px 8px;
  border: 1px solid var(--ink);
  color: var(--ink);
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.calc-diff-pill {
  padding: 2px 8px;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 1px solid var(--rule);
}
.calc-diff-pill.easy   { color: #2E7D32; border-color: #2E7D32; }
.calc-diff-pill.medium { color: var(--ink-mid); border-color: var(--ink-mid); }
.calc-diff-pill.hard   { color: var(--accent); border-color: var(--accent); }

.calc-meta-sep   { color: var(--rule); }
.calc-meta-time  { font-weight: 600; color: var(--ink-mid); }
.calc-meta-source {
  font-style: italic;
  font-size: 10.5px;
  color: var(--ink-light);
}

.calc-section { margin-bottom: 18px; }
.calc-section .label {
  display: block;
  margin-bottom: 6px;
  color: var(--ink);
}

.calc-problem {
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink);
}
.calc-problem p:last-child { margin-bottom: 0; }
.calc-problem table.md-table {
  font-size: 12.5px;
  margin: 8px 0 4px;
}

.calc-given-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 13px;
}
.calc-given-table tr {
  border-bottom: 1px dotted var(--rule);
}
.calc-given-table tr:last-child { border-bottom: none; }
.calc-given-label {
  padding: 5px 10px 5px 0;
  color: var(--ink-mid);
}
.calc-given-value {
  padding: 5px 10px;
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--ink);
  text-align: right;
  white-space: nowrap;
}
.calc-given-note {
  padding: 5px 0 5px 10px;
  font-size: 11px;
  color: var(--ink-light);
  font-style: italic;
}

.calc-formula-list {
  list-style: none;
  padding: 10px 14px;
  margin: 0;
  background: var(--paper-dark);
  border-left: 3px solid var(--ink-mid);
}
.calc-formula-list li {
  font-family: 'JetBrains Mono', 'Consolas', 'Courier New', monospace;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink);
}
.calc-formula-list li + li {
  margin-top: 4px;
  padding-top: 4px;
  border-top: 1px dashed var(--rule);
}

.calc-reveal-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 12px 18px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: var(--font-body);
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.calc-reveal-btn:hover { background: var(--accent); border-color: var(--accent); }
.calc-reveal-btn.open  { background: transparent; color: var(--ink); }
.calc-reveal-btn.open:hover { background: var(--paper-dark); }
.calc-reveal-btn svg { transition: transform 0.2s; }
.calc-reveal-btn.open svg { transform: rotate(180deg); }

.calc-solution {
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.2s, margin-top 0.2s;
}
.calc-solution.closed {
  max-height: 0;
  opacity: 0;
  margin-top: 0;
  pointer-events: none;
}
.calc-solution.open {
  max-height: 8000px;
  opacity: 1;
  margin-top: 18px;
}

.calc-part {
  border-left: 2px solid var(--accent);
  padding: 10px 0 10px 16px;
  margin-bottom: 16px;
}
.calc-part-head { margin-bottom: 8px; }
.calc-part-prompt {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  color: var(--ink);
}
.calc-part-prompt strong { color: var(--accent); }

.calc-working {
  list-style: none;
  counter-reset: workstep;
  padding: 0;
  margin: 8px 0 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-mid);
}
.calc-working li {
  position: relative;
  padding: 3px 0 3px 28px;
  font-family: 'JetBrains Mono', 'Consolas', 'Courier New', monospace;
  font-size: 12.5px;
}
.calc-working li::before {
  counter-increment: workstep;
  content: counter(workstep);
  position: absolute;
  left: 0;
  top: 4px;
  width: 18px;
  height: 18px;
  font-family: var(--font-body);
  font-size: 9px;
  font-weight: 700;
  color: var(--ink-light);
  text-align: right;
  padding-right: 6px;
  border-right: 1px solid var(--rule);
  line-height: 1.3;
}
.calc-working li strong { color: var(--accent); font-weight: 700; }

.calc-final-answer {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 12px;
  background: var(--paper-dark);
  border-top: 2px solid var(--accent);
  margin-top: 6px;
  flex-wrap: wrap;
}
.calc-final-answer .label {
  display: inline-block;
  margin-bottom: 0;
  color: var(--accent);
}
.calc-final-value {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 900;
  color: var(--ink);
  letter-spacing: 0.01em;
}
.calc-final-unit {
  font-size: 11px;
  color: var(--ink-light);
  font-style: italic;
}

.calc-intuition {
  margin-top: 18px;
  padding: 14px 16px;
  background: var(--paper-dark);
  border-left: 3px solid var(--ink);
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-mid);
}
.calc-intuition .label { display: block; margin-bottom: 6px; color: var(--ink); }
.calc-intuition p:last-child { margin-bottom: 0; }

@media (max-width: 640px) {
  .calc-wrap { padding: 16px 12px 60px; }
  .calc-card { padding: 16px 14px; }
  .calc-card-head { gap: 10px; }
  .calc-num { font-size: 18px; min-width: 28px; }
  .calc-title { font-size: 16px; }
  .calc-meta { font-size: 10.5px; gap: 6px; }
  .calc-meta-source { width: 100%; }
  .calc-controls { gap: 8px; }
  .calc-bulk-btn { padding: 5px 10px; }
  .calc-formula-list { padding: 8px 10px; }
  .calc-formula-list li { font-size: 11.5px; line-height: 1.55; }
  .calc-working { font-size: 12px; }
  .calc-working li { font-size: 11.5px; padding-left: 24px; }
  .calc-final-value { font-size: 15px; }
  .calc-problem table.md-table { font-size: 11.5px; }
  .calc-given-table { font-size: 12px; }
}