@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,300;0,9..144,400;0,9..144,600;0,9..144,700;1,9..144,300;1,9..144,400&family=Atkinson+Hyperlegible:ital,wght@0,400;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* ──────────────────────────────────────────
   DESIGN TOKENS
────────────────────────────────────────── */
:root {
  --bg:          #f7f4ef;
  --bg-alt:      #ede9e1;
  --surface:     #ffffff;
  --border:      #d5cfc4;
  --border-dark: #b5afa4;
  --text:        #1c1917;
  --text-muted:  #78716c;
  --text-light:  #a8a29e;
  --primary:     #1e3a5f;
  --primary-mid: #2c5282;
  --accent:      #c2651a;
  --accent-light:#e07a30;
  --success:     #166534;
  --success-bg:  #dcfce7;
  --error:       #991b1b;
  --error-bg:    #fee2e2;
  --warn:        #92400e;
  --warn-bg:     #fef3c7;
  --nav-h:       64px;
  --radius:      10px;
  --radius-sm:   6px;
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.07), 0 1px 2px rgba(0,0,0,0.05);
  --shadow:      0 4px 12px rgba(0,0,0,0.08), 0 1px 4px rgba(0,0,0,0.05);
  --shadow-lg:   0 8px 32px rgba(0,0,0,0.12), 0 2px 8px rgba(0,0,0,0.06);

  /* Topic badge colors */
  --t-interface: #1e40af; --t-interface-bg: #dbeafe;
  --t-scripting: #5b21b6; --t-scripting-bg: #ede9fe;
  --t-physics:   #065f46; --t-physics-bg:   #d1fae5;
  --t-animation: #9d174d; --t-animation-bg: #fce7f3;
  --t-audio:     #92400e; --t-audio-bg:     #fef3c7;
  --t-lighting:  #9a3412; --t-lighting-bg:  #ffedd5;
  --t-ui:        #0c4a6e; --t-ui-bg:        #e0f2fe;
  --t-2d:        #14532d; --t-2d-bg:        #f0fdf4;
  --t-workflow:  #374151; --t-workflow-bg:  #f3f4f6;
}

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

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

body {
  font-family: 'Atkinson Hyperlegible', Georgia, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  padding-top: var(--nav-h);
  min-height: 100vh;
}

/* Subtle dot-grid background texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(circle, var(--border) 1px, transparent 1px);
  background-size: 28px 28px;
  opacity: 0.4;
  z-index: 0;
}

.page-content { position: relative; z-index: 1; }

h1, h2, h3, h4 {
  font-family: 'Fraunces', Georgia, serif;
  color: var(--primary);
  line-height: 1.2;
}

a { color: var(--primary-mid); text-decoration: none; }
a:hover { color: var(--accent); }

code, pre {
  font-family: 'JetBrains Mono', 'Courier New', monospace;
  font-size: 0.875em;
}

ul { list-style: none; }
button { cursor: pointer; font-family: inherit; }
input, select { font-family: inherit; }

/* ──────────────────────────────────────────
   NAVIGATION
────────────────────────────────────────── */
#site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  display: flex;
  align-items: center;
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-logo {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  margin-right: 40px;
  flex-shrink: 0;
}
.nav-logo-title {
  font-family: 'Fraunces', serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.01em;
  line-height: 1.1;
}
.nav-logo-sub {
  font-size: 0.68rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 700;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 1;
}

.nav-links a {
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s, background 0.15s;
  position: relative;
}
.nav-links a:hover { color: var(--primary); background: var(--bg); }
.nav-links a.active {
  color: var(--accent);
  background: #fff5ed;
}
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 14px; right: 14px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  padding: 8px;
  margin-left: auto;
}
.nav-hamburger span {
  display: block;
  width: 22px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.2s;
}

.nav-mobile-overlay {
  display: none;
  position: fixed;
  inset: var(--nav-h) 0 0;
  background: rgba(0,0,0,0.4);
  z-index: 99;
}

.nav-mobile-menu {
  position: fixed;
  top: var(--nav-h); right: 0;
  width: 220px;
  background: var(--surface);
  border-left: 1px solid var(--border);
  height: calc(100vh - var(--nav-h));
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  z-index: 100;
  transform: translateX(100%);
  transition: transform 0.25s;
}
.nav-mobile-menu.open { transform: translateX(0); }
.nav-mobile-menu a {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  color: var(--text-muted);
  display: block;
}
.nav-mobile-menu a.active { color: var(--accent); background: #fff5ed; }

/* ──────────────────────────────────────────
   LAYOUT WRAPPERS
────────────────────────────────────────── */
.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

.page-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 32px 0;
}
.page-header .container { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.page-header-text h1 { font-size: 2rem; margin-bottom: 4px; }
.page-header-text p { color: var(--text-muted); font-size: 0.95rem; }

.main-content { padding: 32px 0 64px; }

/* ──────────────────────────────────────────
   FILTER BAR
────────────────────────────────────────── */
.filter-bar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
  position: sticky;
  top: var(--nav-h);
  z-index: 50;
  box-shadow: var(--shadow-sm);
}
.filter-bar .container {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.filter-label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-muted);
  flex-shrink: 0;
}
.filter-pills { display: flex; flex-wrap: wrap; gap: 6px; flex: 1; }
.filter-pill {
  padding: 5px 14px;
  border-radius: 20px;
  border: 1.5px solid var(--border);
  background: var(--surface);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}
.filter-pill:hover { border-color: var(--primary-mid); color: var(--primary); }
.filter-pill.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.search-input {
  padding: 7px 14px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  font-size: 0.875rem;
  background: var(--bg);
  color: var(--text);
  outline: none;
  transition: border-color 0.15s;
  min-width: 180px;
}
.search-input:focus { border-color: var(--primary-mid); background: white; }

/* ──────────────────────────────────────────
   GENERIC CARD
────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

/* ──────────────────────────────────────────
   TOPIC BADGES
────────────────────────────────────────── */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}
.badge-interface  { color: var(--t-interface);  background: var(--t-interface-bg);  }
.badge-scripting  { color: var(--t-scripting);  background: var(--t-scripting-bg);  }
.badge-physics    { color: var(--t-physics);    background: var(--t-physics-bg);    }
.badge-animation  { color: var(--t-animation);  background: var(--t-animation-bg);  }
.badge-audio      { color: var(--t-audio);      background: var(--t-audio-bg);      }
.badge-lighting   { color: var(--t-lighting);   background: var(--t-lighting-bg);   }
.badge-ui         { color: var(--t-ui);         background: var(--t-ui-bg);         }
.badge-2d         { color: var(--t-2d);         background: var(--t-2d-bg);         }
.badge-workflow   { color: var(--t-workflow);   background: var(--t-workflow-bg);   }

/* ──────────────────────────────────────────
   BUTTONS
────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 700;
  border: 1.5px solid transparent;
  transition: all 0.15s;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}
.btn-primary:hover { background: var(--primary-mid); color: white; border-color: var(--primary-mid); }

.btn-secondary {
  background: var(--surface);
  color: var(--primary);
  border-color: var(--border-dark);
}
.btn-secondary:hover { border-color: var(--primary); background: var(--bg); color: var(--primary); }

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

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: transparent;
}
.btn-ghost:hover { background: var(--bg-alt); color: var(--text); }

.btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* ──────────────────────────────────────────
   STATS ROW (for index/results)
────────────────────────────────────────── */
.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat-number {
  font-family: 'Fraunces', serif;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}
.stat-label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ──────────────────────────────────────────
   EMPTY STATE
────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 64px 24px;
  color: var(--text-muted);
}
.empty-state-icon { font-size: 3rem; margin-bottom: 16px; }
.empty-state h3 { font-size: 1.1rem; margin-bottom: 8px; }

/* ──────────────────────────────────────────
   FLASHCARD PAGE
────────────────────────────────────────── */
.flashcard-stage {
  max-width: 640px;
  margin: 0 auto;
}

.flashcard-counter {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}
.counter-text { font-size: 0.875rem; color: var(--text-muted); font-weight: 700; }
.progress-bar-wrap {
  flex: 1;
  height: 4px;
  background: var(--bg-alt);
  border-radius: 4px;
  margin: 0 16px;
  overflow: hidden;
}
.progress-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 4px;
  transition: width 0.3s;
}

.flashcard-scene {
  perspective: 1000px;
  height: 320px;
  margin-bottom: 24px;
  cursor: pointer;
}
.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.55s cubic-bezier(0.4, 0, 0.2, 1);
}
.flashcard-scene.flipped .flashcard-inner { transform: rotateY(180deg); }

.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 40px;
  text-align: center;
}
.flashcard-face.back {
  transform: rotateY(180deg);
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}
.flashcard-face-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.flashcard-face.back .flashcard-face-label { color: rgba(255,255,255,0.55); }
.flashcard-face h2 {
  font-family: 'Fraunces', serif;
  font-size: 1.35rem;
  line-height: 1.4;
  color: var(--text);
}
.flashcard-face.back h2 { color: white; font-size: 1.15rem; }
.flashcard-hint {
  position: absolute;
  bottom: 16px;
  font-size: 0.72rem;
  color: var(--text-light);
}
.flashcard-face.back .flashcard-hint { color: rgba(255,255,255,0.4); }

.flashcard-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

/* ──────────────────────────────────────────
   QUIZ PAGE
────────────────────────────────────────── */
.quiz-stage { max-width: 680px; margin: 0 auto; }

.quiz-progress-bar {
  height: 6px;
  background: var(--bg-alt);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 28px;
}
.quiz-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 6px;
  transition: width 0.4s;
}

.quiz-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.quiz-question-area {
  padding: 32px 32px 24px;
  border-bottom: 1px solid var(--border);
}
.quiz-q-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}
.quiz-q-num {
  font-family: 'Fraunces', serif;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
}
.quiz-question-text {
  font-size: 1.1rem;
  line-height: 1.55;
  color: var(--text);
}

.quiz-options { padding: 16px 24px 24px; display: flex; flex-direction: column; gap: 10px; }
.quiz-option {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 18px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  cursor: pointer;
  transition: all 0.15s;
  font-size: 0.93rem;
  text-align: left;
  width: 100%;
}
.quiz-option:hover:not(:disabled) {
  border-color: var(--primary-mid);
  background: white;
  box-shadow: var(--shadow-sm);
}
.quiz-option-letter {
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--border);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
  transition: all 0.15s;
}
.quiz-option.correct {
  border-color: var(--success);
  background: var(--success-bg);
}
.quiz-option.correct .quiz-option-letter {
  background: var(--success);
  color: white;
}
.quiz-option.wrong {
  border-color: var(--error);
  background: var(--error-bg);
}
.quiz-option.wrong .quiz-option-letter {
  background: var(--error);
  color: white;
}
.quiz-option:disabled { cursor: default; }

.quiz-explanation {
  margin: 0 24px 24px;
  padding: 14px 16px;
  background: #fffbf5;
  border: 1px solid #e8d5b0;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--text);
  display: none;
  border-left: 3px solid var(--accent);
}
.quiz-explanation.visible { display: block; }
.quiz-explanation strong { color: var(--accent); }

.quiz-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: flex-end;
}

/* Quiz results */
.quiz-results-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 48px;
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}
.quiz-score-circle {
  width: 120px; height: 120px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 3px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
}
.quiz-score-pct {
  font-family: 'Fraunces', serif;
  font-size: 2.2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--accent);
}
.quiz-score-label { font-size: 0.7rem; color: var(--text-muted); font-weight: 700; text-transform: uppercase; }

/* ──────────────────────────────────────────
   NOTES PAGE
────────────────────────────────────────── */
.notes-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
  align-items: start;
}

.notes-sidebar {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  position: sticky;
  top: calc(var(--nav-h) + 80px);
}
.notes-sidebar-title {
  padding: 14px 18px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}
.notes-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 18px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: all 0.15s;
  text-decoration: none;
}
.notes-nav-item:last-child { border-bottom: none; }
.notes-nav-item:hover { background: var(--bg); color: var(--text); }
.notes-nav-item.active { background: #fff5ed; color: var(--accent); font-weight: 700; }
.notes-nav-item .nav-icon { font-size: 1rem; }

.notes-topic-content {}
.notes-topic-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}
.notes-topic-icon {
  width: 52px; height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.notes-topic-intro { font-size: 0.93rem; color: var(--text-muted); line-height: 1.7; margin-bottom: 24px; }

.notes-accordion {}
.notes-accordion-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 10px;
  overflow: hidden;
}
.notes-accordion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--primary);
  background: var(--surface);
  transition: background 0.15s;
}
.notes-accordion-header:hover { background: var(--bg); }
.notes-accordion-header.open { background: var(--primary); color: white; }
.notes-accordion-chevron { transition: transform 0.25s; }
.notes-accordion-header.open .notes-accordion-chevron { transform: rotate(180deg); }
.notes-accordion-body {
  display: none;
  padding: 20px 20px 24px;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
  line-height: 1.75;
}
.notes-accordion-body.open { display: block; }
.notes-accordion-body p { margin-bottom: 12px; }
.notes-accordion-body ul, .notes-accordion-body ol {
  margin: 8px 0 12px 20px;
  list-style: disc;
}
.notes-accordion-body ol { list-style: decimal; }
.notes-accordion-body li { margin-bottom: 6px; }
.notes-accordion-body code {
  background: var(--bg-alt);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--accent);
}
.notes-accordion-body strong { color: var(--primary); }
.notes-accordion-body .tip-box {
  background: var(--warn-bg);
  border: 1px solid #f5d89e;
  border-left: 3px solid var(--warn);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin: 12px 0;
  font-size: 0.875rem;
  color: var(--warn);
}
.notes-accordion-body .info-box {
  background: var(--t-interface-bg);
  border: 1px solid #bfdbfe;
  border-left: 3px solid var(--t-interface);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin: 12px 0;
  font-size: 0.875rem;
  color: var(--t-interface);
}

.exam-tips-card {
  background: linear-gradient(135deg, #fff7ed, #fff5f5);
  border: 1px solid #f5d8b0;
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-top: 24px;
}
.exam-tips-card h4 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.exam-tips-card ul { list-style: none; }
.exam-tips-card li {
  padding: 5px 0;
  padding-left: 20px;
  font-size: 0.875rem;
  position: relative;
  color: var(--text);
}
.exam-tips-card li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* ──────────────────────────────────────────
   SNIPPETS PAGE
────────────────────────────────────────── */
.snippets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(540px, 1fr));
  gap: 20px;
}

.snippet-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.snippet-header {
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}
.snippet-meta {}
.snippet-title { font-weight: 700; font-size: 1rem; color: var(--primary); margin-bottom: 4px; }
.snippet-desc { font-size: 0.825rem; color: var(--text-muted); }
.snippet-badges { display: flex; gap: 6px; flex-shrink: 0; }

.snippet-code-wrap { position: relative; }
.snippet-copy-btn {
  position: absolute;
  top: 10px; right: 10px;
  padding: 5px 12px;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 4px;
  color: rgba(255,255,255,0.8);
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s;
  z-index: 2;
}
.snippet-copy-btn:hover { background: rgba(255,255,255,0.2); color: white; }
.snippet-copy-btn.copied { color: #86efac; border-color: #86efac; }

/* Prism overrides for our theme */
pre[class*="language-"] {
  margin: 0 !important;
  border-radius: 0 !important;
  font-size: 0.82rem !important;
  background: #1e2d4a !important;
  max-height: 320px;
  overflow-y: auto;
}

/* Difficulty pill */
.diff-beginner  { color: #065f46; background: #d1fae5; }
.diff-intermediate { color: #92400e; background: #fef3c7; }
.diff-advanced  { color: #991b1b; background: #fee2e2; }

/* ──────────────────────────────────────────
   GLOSSARY PAGE
────────────────────────────────────────── */
.glossary-alpha {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 24px;
}
.alpha-btn {
  width: 32px; height: 32px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: var(--surface);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
}
.alpha-btn:hover { border-color: var(--primary-mid); color: var(--primary); }
.alpha-btn.active { background: var(--primary); color: white; border-color: var(--primary); }
.alpha-btn.inactive { opacity: 0.3; cursor: default; }

.glossary-list {}
.glossary-letter-group { margin-bottom: 32px; }
.glossary-letter-heading {
  font-family: 'Fraunces', serif;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
}

.glossary-term {
  display: flex;
  gap: 20px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.glossary-term:last-child { border-bottom: none; }
.glossary-term-name {
  font-weight: 700;
  font-size: 0.97rem;
  color: var(--primary);
  flex: 0 0 200px;
  padding-top: 2px;
}
.glossary-term-def { font-size: 0.9rem; color: var(--text); line-height: 1.65; flex: 1; }

/* ──────────────────────────────────────────
   HOME PAGE
────────────────────────────────────────── */
.home-hero {
  background: var(--primary);
  padding: 60px 0 48px;
  position: relative;
  overflow: hidden;
}
.home-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 70% 50%, rgba(194,101,26,0.2) 0%, transparent 60%),
                    radial-gradient(circle at 20% 80%, rgba(255,255,255,0.04) 0%, transparent 40%);
}
.home-hero .container { position: relative; z-index: 1; }
.home-hero-eyebrow {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent-light);
  margin-bottom: 12px;
}
.home-hero h1 {
  font-size: 2.75rem;
  color: white;
  max-width: 600px;
  margin-bottom: 16px;
  line-height: 1.15;
}
.home-hero p {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.72);
  max-width: 520px;
  margin-bottom: 28px;
  line-height: 1.7;
}
.home-hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

.section-title {
  font-family: 'Fraunces', serif;
  font-size: 1.5rem;
  color: var(--primary);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.study-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 48px;
}
.study-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-decoration: none;
  transition: all 0.2s;
  display: block;
}
.study-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--primary-mid);
  color: inherit;
}
.study-card-icon { font-size: 2rem; margin-bottom: 12px; }
.study-card-title { font-weight: 700; font-size: 1rem; color: var(--primary); margin-bottom: 4px; }
.study-card-desc { font-size: 0.825rem; color: var(--text-muted); }
.study-card-count { margin-top: 14px; font-size: 0.78rem; font-weight: 700; color: var(--accent); }

.domains-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 14px;
}
.domain-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.domain-weight {
  font-family: 'Fraunces', serif;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
  width: 52px;
  text-align: right;
}
.domain-info {}
.domain-name { font-weight: 700; font-size: 0.93rem; color: var(--primary); }
.domain-desc { font-size: 0.8rem; color: var(--text-muted); margin-top: 2px; }

/* ──────────────────────────────────────────
   RESPONSIVE
────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }

  .notes-layout { grid-template-columns: 1fr; }
  .notes-sidebar { position: static; }
  .notes-sidebar { display: none; }
  .notes-sidebar.mobile-open { display: block; }

  .snippets-grid { grid-template-columns: 1fr; }

  .flashcard-scene { height: 260px; }
  .home-hero h1 { font-size: 1.9rem; }

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

  .filter-bar .container { gap: 8px; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .quiz-question-area { padding: 20px 16px 16px; }
  .quiz-options { padding: 12px 12px 16px; }
  .quiz-results-card { padding: 32px 20px; }
  .home-hero { padding: 40px 0 32px; }
  .home-hero h1 { font-size: 1.6rem; }
}

/* ──────────────────────────────────────────
   TRANSITIONS
────────────────────────────────────────── */
.fade-in {
  animation: fadeIn 0.3s ease;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.card-reveal {
  animation: cardReveal 0.4s cubic-bezier(0.2, 0, 0, 1);
}
@keyframes cardReveal {
  from { opacity: 0; transform: scale(0.97); }
  to   { opacity: 1; transform: scale(1); }
}