:root {
  --bg-primary: #070b14;
  --bg-secondary: #0d1527;
  --bg-card: #131f38;
  --bg-card-hover: #1c2c4e;
  --border-color: #233454;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --accent-cyan: #38bdf8;
  --accent-blue: #2563eb;
  --accent-gold: #fbbf24;
  --accent-green: #22c55e;
  --accent-red: #ef4444;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* Header & Top Bar */
header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

.header-top {
  max-width: 1400px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.logo-group {
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 1.2rem;
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.3);
}

.logo-text h1 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.3px;
}

.logo-text p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.external-links {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.nav-ext-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 600;
  text-decoration: none;
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.nav-ext-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: translateY(-1px);
}

.nav-ext-btn.accent {
  background: rgba(56, 189, 248, 0.12);
  border-color: rgba(56, 189, 248, 0.4);
  color: var(--accent-cyan);
}

/* Tabs Bar */
.tabs-bar {
  background: rgba(13, 21, 39, 0.8);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  overflow-x: auto;
  scrollbar-width: none;
}

.tabs-bar::-webkit-scrollbar {
  display: none;
}

.tabs-container {
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
  padding: 0 24px;
  display: flex;
  gap: 6px;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 12px 16px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.03);
}

.tab-btn.active {
  color: var(--accent-cyan);
  border-bottom-color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.06);
}

/* Main Container */
main {
  flex: 1;
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  padding: 24px;
}

.tab-content {
  display: none;
  animation: fadeIn 0.25s ease;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Common Card & Typography */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 8px;
}

.card-title {
  font-size: 1.15rem;
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  gap: 8px;
}

.badge {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  background: var(--accent-blue);
  color: #fff;
}

.badge.gold {
  background: #78350f;
  color: #fef3c7;
  border: 1px solid #b45309;
}

.badge.green {
  background: #14532d;
  color: #bbf7d0;
  border: 1px solid #16a34a;
}

/* Written Study Brief Tab */
.brief-actions {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  background: var(--accent-blue);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.85rem;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-action:hover {
  background: #1d4ed8;
  transform: translateY(-1px);
}

.btn-action.secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-action.secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
}

.written-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 18px;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  transition: border-color 0.2s ease;
}

.category-card:hover {
  border-color: #3b82f6;
}

.category-card h3 {
  font-size: 1rem;
  color: var(--accent-cyan);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.category-content {
  font-size: 0.88rem;
  color: #cbd5e1;
  line-height: 1.65;
}

.category-content strong {
  color: var(--accent-gold);
  background: rgba(251, 191, 36, 0.08);
  padding: 1px 4px;
  border-radius: 3px;
}

/* Draw the Chart Tab */
.chart-viewer-banner {
  background: linear-gradient(135deg, rgba(13, 21, 39, 0.9), rgba(19, 31, 56, 0.9));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 24px;
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
}

.chart-thumbnail {
  width: 220px;
  height: 140px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--accent-cyan);
  cursor: pointer;
  transition: transform 0.2s ease;
}

.chart-thumbnail:hover {
  transform: scale(1.03);
}

.chart-info {
  flex: 1;
  min-width: 260px;
}

.stops-browser {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
}

@media (max-width: 900px) {
  .stops-browser {
    grid-template-columns: 1fr;
  }
}

.stops-list-container {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  height: 620px;
  display: flex;
  flex-direction: column;
}

.stops-search-box {
  padding: 12px;
  border-bottom: 1px solid var(--border-color);
}

.stops-search-input {
  width: 100%;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

.stops-scroll-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.stop-item {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  transition: all 0.15s ease;
  border: 1px solid transparent;
}

.stop-item:hover {
  background: var(--bg-card-hover);
}

.stop-item.active {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--accent-cyan);
  color: #fff;
  font-weight: 600;
}

.stop-num {
  font-size: 0.75rem;
  font-weight: 700;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--accent-cyan);
  font-family: monospace;
}

.stop-details-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  height: 620px;
  overflow-y: auto;
}

/* Scene Illustrations Carousel */
.scenes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.scene-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.scene-img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  display: block;
}

.scene-body {
  padding: 16px;
}

.scene-body h4 {
  color: var(--accent-cyan);
  font-size: 0.95rem;
  margin-bottom: 6px;
}

.scene-narrative {
  font-size: 0.85rem;
  color: #cbd5e1;
  margin-bottom: 8px;
}

.scene-pegs {
  font-size: 0.78rem;
  color: var(--accent-gold);
  font-style: italic;
}

/* Audio Drills Tab */
.audio-player-panel {
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-card) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
}

.player-track-info {
  margin-bottom: 16px;
}

.player-track-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent-cyan);
  margin-bottom: 4px;
}

.player-track-purpose {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.timeline-container {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.seek-bar {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  background: #334155;
  border-radius: 3px;
  cursor: pointer;
  outline: none;
}

.seek-bar::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent-cyan);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-cyan);
}

.time-display {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-muted);
  width: 90px;
  text-align: center;
}

.player-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-play {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent-cyan);
  color: #060911;
  border: none;
  font-size: 1.2rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.4);
}

.btn-play:hover {
  transform: scale(1.05);
  background: #7dd3fc;
}

.rate-group {
  display: flex;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.rate-btn {
  background: var(--bg-card);
  color: var(--text-muted);
  border: none;
  padding: 6px 12px;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
}

.rate-btn.active {
  background: var(--accent-blue);
  color: #fff;
}

.loop-btn {
  background: var(--bg-card);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
}

.loop-btn.active {
  border-color: var(--accent-green);
  color: var(--accent-green);
  background: rgba(34, 197, 94, 0.1);
}

.audio-layout {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 20px;
}

@media (max-width: 900px) {
  .audio-layout {
    grid-template-columns: 1fr;
  }
}

.tracks-playlist {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  max-height: 580px;
  overflow-y: auto;
  padding: 8px;
}

.track-item {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 4px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.track-item:hover {
  background: var(--bg-card-hover);
}

.track-item.active {
  background: rgba(56, 189, 248, 0.12);
  border-color: var(--accent-cyan);
}

.track-item-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 2px;
}

.track-item-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
}

.transcript-pane {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  max-height: 580px;
  overflow-y: auto;
}

.transcript-pane h3 {
  color: var(--accent-cyan);
  font-size: 1rem;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.transcript-body {
  font-size: 0.88rem;
  color: #cbd5e1;
  white-space: pre-wrap;
  line-height: 1.7;
}

/* Flashcards Tab */
.flashcards-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.deck-select {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  outline: none;
}

.flashcard-wrapper {
  perspective: 1000px;
  max-width: 680px;
  height: 380px;
  margin: 0 auto 24px auto;
  cursor: pointer;
}

.flashcard {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.4s ease;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.card-face.front {
  background: linear-gradient(135deg, #101c36 0%, #0d1527 100%);
}

.card-face.back {
  background: linear-gradient(135deg, #0d1527 0%, #172544 100%);
  transform: rotateY(180deg);
  border-color: var(--accent-blue);
}

.card-category-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.card-text-center {
  font-size: 1.25rem;
  font-weight: 600;
  text-align: center;
  color: #fff;
  line-height: 1.5;
  margin: auto 0;
  overflow-y: auto;
  max-height: 220px;
}

.card-hint {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
}

.card-notes {
  font-size: 0.85rem;
  color: var(--accent-gold);
  background: rgba(251, 191, 36, 0.08);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent-gold);
  margin-top: 10px;
}

.deck-nav-buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.btn-nav {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-nav:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
}

.card-counter {
  font-family: monospace;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* NotebookLM Artifacts Box */
.nlm-artifacts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.nlm-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  text-decoration: none;
  color: inherit;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.2s ease;
}

.nlm-card:hover {
  border-color: var(--accent-cyan);
  background: var(--bg-card);
  transform: translateY(-2px);
}

.nlm-type-pill {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 2px 6px;
  border-radius: 4px;
  background: #3b82f6;
  color: #fff;
}

/* Reference Tables */
.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-top: 12px;
}

.ref-table th {
  background: var(--bg-secondary);
  color: var(--accent-cyan);
  padding: 10px 12px;
  border-bottom: 2px solid var(--border-color);
  text-align: left;
}

.ref-table td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border-color);
}

.ref-table tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

/* Print Stylesheet */
@media print {
  body {
    background: #fff !important;
    color: #000 !important;
  }
  header, .brief-actions, .external-links, .tabs-bar, footer {
    display: none !important;
  }
  main {
    max-width: 100% !important;
    padding: 0 !important;
  }
  .tab-content {
    display: none !important;
  }
  #tab-written {
    display: block !important;
  }
  .category-card {
    background: #fff !important;
    color: #000 !important;
    border: 1px solid #ccc !important;
    page-break-inside: avoid;
    margin-bottom: 10px !important;
    padding: 10px !important;
  }
  .category-content {
    color: #111 !important;
    font-size: 9pt !important;
  }
  .category-content strong {
    color: #000 !important;
    text-decoration: underline;
    background: none !important;
  }
}

/* Short recall cards, release 2026-09-22 */
[hidden]{display:none!important}.memory-card{max-width:1000px;margin:24px auto;padding:clamp(20px,4vw,44px);border:1px solid #34628e;border-radius:22px;background:linear-gradient(145deg,#102339,#091421);box-shadow:0 20px 50px #0003}.memory-card h2{font-size:clamp(1.25rem,3vw,1.9rem);line-height:1.45;margin:22px 0 10px}.memory-hint,.memory-note,#session-status{color:#a6b9cc;font-size:.9rem;margin:12px 0}.memory-card button{margin:6px 6px 6px 0}#card-answer{border-top:1px solid #385064;margin-top:22px;padding-top:20px}#card-picture{width:100%;height:auto;display:block;border-radius:12px}#card-back-text{font-size:clamp(1.2rem,2.5vw,1.7rem);font-weight:650;color:#e6f4ff;line-height:1.5;margin:22px 0}#card-answer details{font-size:.8rem;color:#8ba5bc}#card-answer summary{cursor:pointer}#grade-buttons{margin-top:18px}#card-light{padding:30px;background:#000;border-radius:12px;text-align:center}.memory-bulb{display:inline-block;width:15px;height:15px;border-radius:50%;margin:10px 30px}#card-light small{display:block;color:#7c8b9e;margin-top:16px}.scene-img{height:auto;object-fit:contain}.scenes-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,360px),1fr))}button:disabled{opacity:.45;cursor:not-allowed}:focus-visible{outline:3px solid #fbbf24;outline-offset:3px}.deck-nav-buttons{flex-wrap:wrap}.memory-card .card-category-tag{position:static}.memory-card .btn-nav{padding:10px 14px}@media(max-width:600px){main{padding:12px}.card{padding:16px}.flashcards-controls{flex-direction:column}.deck-select{max-width:100%;width:100%}.player-controls,.player-controls>div{flex-wrap:wrap}.external-links{flex-wrap:wrap}.memory-card{padding:18px}.stops-browser{grid-template-columns:1fr}.stops-list-container{height:260px}.stop-details-card{height:auto;max-height:440px}}