/* ============================================================
   DRVLA Project Page -- Custom CSS
   Clean academic aesthetic, no frameworks
   ============================================================ */

/* --- CSS Variables --- */
:root {
  --accent: #3478f6;
  --accent-hover: #2563d4;
  --bg: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #555;
  --nav-bg: #4a4a4a;
  --nav-text: #fff;
  --section-bg: #f8f9fa;
  --card-bg: #fff;
  --card-border: #e0e0e0;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1100px;
}

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

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

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

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

a:hover {
  color: var(--accent-hover);
}

/* --- Navigation Bar --- */
.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 48px;
  background: var(--nav-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
}

.nav-brand {
  color: var(--nav-text);
  font-size: 1rem;
  font-weight: 700;
  white-space: nowrap;
  padding: 0 16px 0 18px;
  flex-shrink: 0;
}

.nav-bar nav {
  display: flex;
  align-items: center;
  gap: 4px;
  max-width: var(--max-width);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

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

.nav-bar a {
  color: var(--nav-text);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  padding: 12px 14px;
  white-space: nowrap;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.nav-bar a:hover {
  color: #ddd;
}

.nav-bar a.active {
  border-bottom-color: var(--accent);
  color: #fff;
}

/* --- Main Content --- */
main {
  margin-top: 60px;
}

/* --- Sections --- */
.section {
  padding: 80px 20px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-wrapper {
  width: 100%;
}

.section-wrapper.section-alt {
  background: var(--section-bg);
}

.section h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text);
  letter-spacing: -0.02em;
}

.section h3 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 16px;
  margin-top: 32px;
  color: var(--text);
}

.section p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.8;
}

.section p:last-child {
  margin-bottom: 0;
}

/* --- Hero Section --- */
.hero {
  text-align: center;
  padding: 100px 20px 80px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero-logo {
  font-size: 3.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 24px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero .conference-badge {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 4px 16px;
  border-radius: 20px;
  margin-bottom: 20px;
  letter-spacing: 0.03em;
}

.hero .authors {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.6;
}

.hero .authors sup {
  color: var(--accent);
  font-weight: 600;
}

.hero .equal-contribution {
  font-size: 0.9rem;
  color: #888;
  margin-bottom: 32px;
}

.hero .buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 48px;
}

.hero .buttons a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--accent);
  color: #fff !important;
  border: 2px solid var(--accent);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #fff !important;
}

.btn-outline {
  background: transparent;
  color: var(--accent) !important;
  border: 2px solid var(--accent);
}

.btn-outline:hover {
  background: var(--accent);
  color: #fff !important;
}

.hero .splash-image {
  max-width: min(900px, 100%);
  margin: 0 auto;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

/* --- Figures --- */
.figure {
  text-align: center;
  margin: 32px auto;
}

.figure img {
  max-width: 100%;
  margin: 0 auto;
  border-radius: 6px;
}

.figure.narrow img {
  max-width: min(800px, 100%);
}

.figure.wide img {
  max-width: min(900px, 100%);
}

.figure-caption {
  font-size: 0.92rem;
  color: #777;
  font-style: italic;
  margin-top: 12px;
  line-height: 1.6;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* Side-by-side figure rows */
.figure-row {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  margin: 32px 0;
}

.figure-row .figure {
  flex: 1;
  margin: 0;
  min-width: 0;
}

.figure-row .figure img {
  max-width: 100%;
}

/* Three-column figure row */
.figure-row-3 {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin: 32px 0;
}

.figure-row-3 .figure {
  flex: 1;
  margin: 0;
  min-width: 0;
}

.figure-row-3 .figure img {
  max-width: 100%;
}

/* 2x2 grid */
.figure-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin: 32px 0;
}

.figure-grid .figure {
  margin: 0;
}

.figure-grid .figure img {
  max-width: 100%;
}

/* --- Feature Cards --- */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 32px 0;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 24px;
  transition: box-shadow 0.2s ease, transform 0.15s ease;
}

.feature-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.feature-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0;
  line-height: 1.65;
}

/* --- Badges --- */
.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.badge.general {
  background: #dcfce7;
  color: #166534;
}

.badge.memorized {
  background: #fef3c7;
  color: #92400e;
}

/* --- Classification Table --- */
.classification-table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.95rem;
}

.classification-table th {
  background: var(--nav-bg);
  color: var(--nav-text);
  font-weight: 600;
  padding: 12px 16px;
  text-align: left;
  white-space: nowrap;
}

.classification-table th:first-child {
  border-radius: 8px 0 0 0;
}

.classification-table th:last-child {
  border-radius: 0 8px 0 0;
}

.classification-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--card-border);
}

.classification-table tbody tr:nth-child(even) {
  background: var(--section-bg);
}

.classification-table tbody tr:hover {
  background: #eef2ff;
}

.classification-table tbody tr:last-child td:first-child {
  border-radius: 0 0 0 8px;
}

.classification-table tbody tr:last-child td:last-child {
  border-radius: 0 0 8px 0;
}

/* --- Stats Table (compact) --- */
.stats-table {
  width: auto;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.9rem;
}

.stats-table th,
.stats-table td {
  padding: 6px 14px;
  text-align: left;
  border-bottom: 1px solid var(--card-border);
}

.stats-table th {
  font-weight: 600;
  color: var(--text);
}

/* --- BibTeX Block --- */
.bibtex-block {
  position: relative;
  background: #1e1e2e;
  color: #cdd6f4;
  font-family: var(--mono);
  font-size: 0.88rem;
  line-height: 1.7;
  padding: 24px 28px;
  border-radius: 10px;
  overflow-x: auto;
  margin: 24px 0;
}

.bibtex-block pre {
  margin: 0;
  white-space: pre;
}

.copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(255, 255, 255, 0.1);
  color: #cdd6f4;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 0.8rem;
  font-family: var(--font);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

.copy-btn.copied {
  background: #166534;
  border-color: #22c55e;
  color: #dcfce7;
}

/* --- Spinner --- */
.spinner {
  display: inline-block;
  width: 32px;
  height: 32px;
  border: 3px solid var(--card-border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-placeholder {
  text-align: center;
  padding: 48px 20px;
  color: var(--text-secondary);
  font-size: 1rem;
}

.loading-placeholder .spinner {
  margin: 0 auto 16px;
}

/* --- Interactive Container Placeholder --- */
#feature-viewer-container,
#feature-browser-container {
  min-height: 200px;
}

/* --- Subsection Label --- */
.subsection-label {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 8px;
}

/* --- Subtitle --- */
.section .subtitle {
  font-size: 1.1rem;
  color: #777;
  margin-bottom: 32px;
}

/* --- Steering Key Findings --- */
.steering-findings {
  margin: 32px 0;
}

.steering-findings .finding {
  padding: 20px 24px;
  border-left: 4px solid var(--accent);
  background: #f0f4ff;
  border-radius: 0 8px 8px 0;
  margin-bottom: 16px;
}

.steering-findings .finding strong {
  color: var(--text);
}

.steering-findings .finding p {
  margin-bottom: 0;
  font-size: 1rem;
}

/* --- Key Finding Box --- */
.key-finding {
  background: #f0f4ff;
  border-left: 4px solid var(--accent);
  padding: 20px 24px;
  border-radius: 0 8px 8px 0;
  margin: 24px 0;
}

.key-finding p {
  margin-bottom: 0;
  font-size: 1rem;
  color: var(--text);
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 32px 20px;
  font-size: 0.88rem;
  color: #999;
  border-top: 1px solid var(--card-border);
}

/* ============================================================
   Responsive Breakpoints
   ============================================================ */

/* --- Tablet / Small Desktop (900px) --- */
@media (max-width: 900px) {
  .hero h1 {
    font-size: 2.2rem;
  }

  .section {
    padding: 60px 20px;
  }

  .hero {
    padding: 80px 20px 60px;
  }

  .figure-row,
  .figure-row-3 {
    flex-direction: column;
  }

  .figure-row .figure,
  .figure-row-3 .figure {
    flex: none;
    width: 100%;
  }

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

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

  .classification-table {
    font-size: 0.85rem;
  }

  .classification-table th,
  .classification-table td {
    padding: 8px 10px;
  }
}

/* --- Large Phone (480px) --- */
@media (max-width: 480px) {
  html {
    font-size: 15px;
  }

  .hero h1 {
    font-size: 1.7rem;
  }

  .hero .authors {
    font-size: 1rem;
  }

  .section h2 {
    font-size: 1.5rem;
  }

  .section h3 {
    font-size: 1.2rem;
  }

  .section {
    padding: 48px 16px;
  }

  .hero {
    padding: 60px 16px 48px;
  }

  .hero .buttons a {
    padding: 8px 18px;
    font-size: 0.88rem;
  }

  .nav-bar a {
    font-size: 0.78rem;
    padding: 12px 10px;
  }

  .feature-card {
    padding: 18px;
  }

  .bibtex-block {
    font-size: 0.78rem;
    padding: 18px 16px;
  }

  .classification-table {
    font-size: 0.8rem;
    display: block;
    overflow-x: auto;
  }
}

/* ============================================================
   Feature Viewer Component Styles
   ============================================================ */

/* Tab bar */
.fv-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
}

.fv-tab {
  background: var(--section-bg);
  border: 1px solid var(--card-border);
  border-radius: 24px;
  padding: 8px 20px;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.fv-tab--active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.fv-tab--active:hover {
  color: #fff;
}

/* Feature viewer content */
.fv-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.fv-description {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
}

/* Stats row */
.fv-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 32px;
  padding: 16px 20px;
  background: var(--section-bg);
  border-radius: 10px;
  border: 1px solid var(--card-border);
}

.fv-stat {
  display: flex;
  flex-direction: column;
  min-width: 120px;
}

.fv-stat-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #888;
  margin-bottom: 4px;
}

.fv-stat-value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text);
}

/* Episode grid */
.fv-episode-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.fv-episode-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  overflow: hidden;
}

.fv-episode-images {
  display: flex;
  gap: 2px;
}

.fv-episode-images img {
  width: 50%;
  aspect-ratio: 1;
  object-fit: cover;
  min-height: 0;
}

.fv-episode-meta {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 6px 8px 2px;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.fv-episode-task {
  font-size: 0.72rem;
  color: #888;
  padding: 0 8px 8px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.fv-note {
  font-size: 0.85rem;
  color: #999;
  font-style: italic;
}

/* Episode card clickable + selected state */
.fv-episode-card {
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.fv-episode-card:hover {
  border-color: var(--accent);
}

.fv-episode-card--selected {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(52, 120, 246, 0.25);
}

/* Expansion panel below episode grid */
.fv-expansion-panel {
  border-top: 1px solid var(--card-border);
  padding: 24px 0 8px;
  margin-top: 8px;
}

.fv-expansion-panel .fv-expansion-header {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-weight: 500;
}

.fv-expansion-panel .fv-expansion-header strong {
  color: var(--text);
}

/* Image strip inside expansion panel uses same styles as activation-viz
   but without the left margin (no heatmap labels to align with initially) */
.fv-expansion-panel .image-strip {
  margin-left: 60px;
}

.fv-expansion-panel .heatmap-container {
  margin-top: 4px;
}

/* ============================================================
   Feature Browser Component Styles
   ============================================================ */

/* Loading and error */
.fb-loading {
  text-align: center;
  padding: 48px 20px;
  color: var(--text-secondary);
}

.fb-spinner {
  display: inline-block;
  width: 32px;
  height: 32px;
  border: 3px solid var(--card-border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 16px;
}

.fb-error {
  text-align: center;
  padding: 32px 20px;
  color: #e53e3e;
}

/* Controls */
.fb-controls {
  margin-bottom: 24px;
}

.fb-controls-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: flex-end;
  margin-bottom: 16px;
}

.fb-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #888;
  margin-bottom: 6px;
}

.fb-search {
  padding: 8px 14px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  font-family: var(--font);
  font-size: 0.9rem;
  width: 160px;
  transition: border-color 0.2s;
}

.fb-search:focus {
  outline: none;
  border-color: var(--accent);
}

.fb-sort {
  padding: 8px 14px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  font-family: var(--font);
  font-size: 0.9rem;
  background: var(--card-bg);
  cursor: pointer;
}

.fb-radios {
  display: flex;
  gap: 14px;
}

.fb-radios label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
}

.fb-stats-bar {
  font-size: 0.88rem;
  color: var(--text-secondary);
  padding: 10px 16px;
  background: var(--section-bg);
  border-radius: 8px;
}

/* Card grid */
.fb-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.fb-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 16px;
  cursor: pointer;
  transition: box-shadow 0.2s, transform 0.15s;
  min-width: 0;
  overflow: hidden;
}

.fb-card:hover {
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  transform: translateY(-1px);
}

.fb-card--expanded {
  grid-column: 1 / -1;
  cursor: default;
}

.fb-card-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.fb-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
}

.fb-card-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 6px;
  font-style: italic;
}

.fb-detail-description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

.fb-card-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.fb-card-stats strong {
  color: var(--text);
}

/* Thumbnails */
.fb-thumbs {
  display: flex;
  gap: 4px;
}

.fb-thumb {
  width: 80px;
  height: 80px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--card-border);
}

.fb-ep-text-list {
  font-size: 0.78rem;
  color: #888;
}

.fb-ep-text {
  padding: 2px 0;
  overflow-wrap: break-word;
  word-wrap: break-word;
}

/* Expanded detail */
.fb-detail {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--card-border);
}

.fb-detail-section {
  margin-bottom: 24px;
}

.fb-detail-section h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.fb-detail-table {
  border-collapse: collapse;
  font-size: 0.88rem;
}

.fb-detail-table td {
  padding: 4px 16px 4px 0;
  border-bottom: 1px solid #eee;
}

.fb-detail-table td:first-child {
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* Detail episode cards */
.fb-detail-episodes {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.fb-detail-ep {
  width: 160px;
  background: var(--section-bg);
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--card-border);
}

.fb-detail-images {
  display: flex;
}

.fb-detail-images img {
  width: 50%;
  aspect-ratio: 1;
  object-fit: cover;
}

.fb-detail-ep-meta {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 6px 8px 2px;
}

.fb-detail-ep-task {
  font-size: 0.7rem;
  color: #888;
  padding: 0 8px 6px;
  line-height: 1.4;
}

/* Episode expansion panel */
.fb-expansion-panel {
  margin-top: 16px;
  padding: 16px 0;
  border-top: 1px solid var(--card-border);
}

.fb-expansion-panel .image-strip {
  margin-left: 60px;
}

.fb-expansion-panel .heatmap-container {
  margin-top: 4px;
}

.fb-expansion-header {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-weight: 500;
}

.fb-expansion-header strong {
  color: var(--text);
}

/* Clickable and selected episode cards */
.fb-detail-ep--clickable {
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.fb-detail-ep--clickable:hover {
  border-color: var(--accent);
}

.fb-detail-ep--selected {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(52, 120, 246, 0.3);
}

/* ============================================================
   Metric Histograms Grid (mh-*)
   ============================================================ */

.mh-grid {
  display: grid;
  grid-template-columns: 60px repeat(4, 1fr);
  gap: 4px 8px;
  align-items: center;
  margin: 24px 0;
}

.mh-row-label {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
  writing-mode: vertical-lr;
  transform: rotate(180deg);
  justify-self: center;
}

.mh-cell {
  min-width: 0;
}

.mh-cell svg {
  width: 100%;
  height: auto;
}

@media (max-width: 900px) {
  .mh-grid {
    grid-template-columns: 40px repeat(4, 1fr);
    gap: 2px 4px;
  }
  .mh-row-label {
    font-size: 0.8rem;
  }
}

@media (max-width: 600px) {
  .mh-grid {
    grid-template-columns: 1fr 1fr;
    gap: 12px 8px;
  }
  .mh-row-label {
    grid-column: 1 / -1;
    writing-mode: horizontal-tb;
    transform: none;
    text-align: left;
    font-size: 1rem;
    padding: 8px 0 0;
    border-top: 1px solid var(--card-border);
  }
}

/* Histogram */
.fb-hist-svg {
  display: block;
  margin: 0 auto;
}

.fb-no-hist {
  font-size: 0.88rem;
  color: #999;
  font-style: italic;
}

/* Pagination */
.fb-pagination {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 6px;
}

.fb-page-btn {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 6px 14px;
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text);
  transition: all 0.15s ease;
}

.fb-page-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.fb-page-btn--active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.fb-page-btn--active:hover {
  color: #fff;
}

.fb-page-btn--disabled {
  opacity: 0.4;
  cursor: default;
}

.fb-page-ellipsis {
  padding: 0 4px;
  color: #999;
}

/* ============================================================
   Responsive: Feature Viewer & Browser
   ============================================================ */

@media (max-width: 900px) {
  .fv-episode-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .fb-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .fb-detail-episodes {
    flex-wrap: wrap;
  }

  .fb-detail-ep {
    width: 140px;
  }
}

@media (max-width: 480px) {
  .fv-episode-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .fb-controls-row {
    flex-direction: column;
    gap: 12px;
  }

  .fb-search {
    width: 100%;
  }

  .fb-thumb {
    width: 60px;
    height: 60px;
  }
}

/* ============================================================
   Abstract TLDR + Dropdown
   ============================================================ */

.abstract-tldr {
  font-size: 1.1rem;
  color: var(--text);
  font-weight: 500;
  line-height: 1.8;
}

.abstract-details {
  margin-top: 16px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  overflow: hidden;
}

.abstract-details summary {
  padding: 12px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  cursor: pointer;
  background: var(--card-bg);
  transition: background 0.2s;
  list-style: none;
}

.abstract-details summary::-webkit-details-marker {
  display: none;
}

.abstract-details summary::before {
  content: '\25B6';
  display: inline-block;
  margin-right: 8px;
  font-size: 0.75rem;
  transition: transform 0.2s;
}

.abstract-details[open] summary::before {
  transform: rotate(90deg);
}

.abstract-details summary:hover {
  background: #eef2ff;
}

.abstract-full {
  padding: 20px;
  border-top: 1px solid var(--card-border);
}

.abstract-full p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.faq-item + .faq-item {
  margin-top: 8px;
}

/* ============================================================
   Activation Visualization Components
   ============================================================ */

/* Feature color palette */
:root {
  --feat-color-0: #3478f6;
  --feat-color-1: #e53e3e;
  --feat-color-2: #38a169;
  --feat-color-3: #d69e2e;
}

/* Toggle button group */
.viz-toggle {
  display: inline-flex;
  gap: 0;
  border: 1px solid var(--card-border);
  border-radius: 24px;
  overflow: hidden;
  margin-bottom: 16px;
}

.viz-toggle-btn {
  background: var(--card-bg);
  border: none;
  padding: 8px 20px;
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.viz-toggle-btn:not(:last-child) {
  border-right: 1px solid var(--card-border);
}

.viz-toggle-btn:hover {
  color: var(--accent);
}

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

.viz-toggle-btn--active:hover {
  color: #fff;
}

.viz-toggle-btn--active-mem {
  background: #dc2626;
  color: #fff;
}

.viz-toggle-btn--active-mem:hover {
  color: #fff;
}

/* Episode tab pills */
.viz-episode-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.viz-ep-tab {
  background: var(--section-bg);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 6px 16px;
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.viz-ep-tab:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.viz-ep-tab--active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.viz-ep-tab--active:hover {
  color: #fff;
}

/* Episode task label */
.viz-task-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-style: italic;
}

/* Feature legend */
.viz-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 16px;
  font-size: 0.85rem;
  font-weight: 600;
}

.viz-legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
}

.viz-legend-swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  flex-shrink: 0;
}

/* --- Image Strip + Heatmap --- */

.image-strip {
  display: flex;
  gap: 3px;
  margin-bottom: 8px;
  margin-left: 60px;  /* align with heatmap bars */
}

.image-strip-frame {
  flex: 1;
  min-width: 0;
  position: relative;
  cursor: pointer;
}

.image-strip-frame img {
  width: 100%;
  height: auto;
  border-radius: 4px;
  border: 2px solid transparent;
  transition: border-color 0.15s;
  display: block;
}

.image-strip-frame:hover img {
  border-color: var(--accent);
}

.image-strip-frame .frame-label {
  position: absolute;
  bottom: 4px;
  left: 4px;
  background: rgba(0, 0, 0, 0.7);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 600;
  padding: 1px 5px;
  border-radius: 3px;
}

.heatmap-container {
  margin-top: 4px;
}

.heatmap-row {
  display: flex;
  align-items: center;
  margin-bottom: 3px;
}

.heatmap-label {
  width: 60px;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
  text-align: right;
  padding-right: 10px;
}

.heatmap-bar {
  flex: 1;
  height: 18px;
  display: flex;
  gap: 0;
  border-radius: 3px;
  overflow: hidden;
  position: relative;
  /* subtle background so empty cells are visible */
  background: rgba(0, 0, 0, 0.03);
}

.heatmap-cell {
  flex: 1;
  position: relative;
  cursor: pointer;
  transition: opacity 0.1s;
}

.heatmap-cell:hover {
  opacity: 0.8;
}

/* --- Option B: Video Scrubber + Chart --- */

.video-scrubber {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.video-scrubber video {
  width: 100%;
  max-width: 640px;
  border-radius: 8px;
  background: #000;
}

.video-controls {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: -8px;
}

.video-controls button {
  background: var(--section-bg);
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 6px 14px;
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--text);
  transition: all 0.15s;
}

.video-controls button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.video-controls .speed-label {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.activation-chart {
  position: relative;
  cursor: crosshair;
}

.activation-chart svg {
  display: block;
  width: 100%;
}

.activation-chart .chart-line {
  fill: none;
  stroke-width: 2;
}

.activation-chart .chart-axis {
  stroke: var(--card-border);
  fill: none;
}

.activation-chart .chart-axis-label {
  font-size: 11px;
  fill: var(--text-secondary);
  font-family: var(--font);
}

.cursor-line {
  stroke: var(--text);
  stroke-width: 1;
  stroke-dasharray: 4 3;
  pointer-events: none;
}

/* Activation readout panel */
.activation-readout {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding: 10px 16px;
  background: var(--section-bg);
  border-radius: 8px;
  border: 1px solid var(--card-border);
  font-size: 0.85rem;
}

.readout-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.readout-swatch {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  flex-shrink: 0;
}

.readout-label {
  font-weight: 600;
  color: var(--text-secondary);
}

.readout-value {
  font-weight: 700;
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.82rem;
}

.readout-step {
  font-weight: 600;
  color: var(--text);
  margin-right: 8px;
}

/* Tooltip */
.viz-tooltip {
  position: fixed;
  background: rgba(26, 26, 26, 0.92);
  color: #fff;
  font-size: 0.78rem;
  font-family: var(--font);
  padding: 6px 10px;
  border-radius: 6px;
  pointer-events: none;
  z-index: 100;
  white-space: nowrap;
  line-height: 1.5;
  transform: translate(-50%, -100%);
  margin-top: -8px;
  display: none;
}

.viz-tooltip.visible {
  display: block;
}

/* Loading state for viz */
.viz-loading {
  text-align: center;
  padding: 32px;
  color: var(--text-secondary);
}

/* --- Wide Screen (1200px+) --- */
@media (min-width: 1200px) {
  .section {
    padding: 100px 20px;
  }

  .hero {
    padding: 120px 20px 100px;
  }
}

/* ============================================================
   Responsive: Activation Viz
   ============================================================ */

@media (max-width: 900px) {
  .image-strip {
    margin-left: 50px;
  }

  .heatmap-label {
    width: 50px;
    font-size: 0.7rem;
  }
}

@media (max-width: 480px) {
  .image-strip {
    margin-left: 40px;
    gap: 2px;
  }

  .heatmap-label {
    width: 40px;
    font-size: 0.65rem;
    padding-right: 6px;
  }

  .image-strip-frame .frame-label {
    font-size: 0.55rem;
    padding: 1px 3px;
  }

  .viz-toggle-btn {
    padding: 6px 14px;
    font-size: 0.78rem;
  }

  .viz-ep-tab {
    padding: 5px 12px;
    font-size: 0.75rem;
  }
}

/* ============================================================
   Steering Visualization (sv-*)
   ============================================================ */

.sv-feature-toggle {
  margin-bottom: 16px;
}

.sv-task-tabs {
  margin-bottom: 12px;
}

.sv-description {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

/* Video pair */
.sv-video-pair {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 12px;
}

.sv-video-col {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.sv-video-col video {
  width: 224px;
  height: 224px;
  border-radius: 6px;
  background: #000;
  object-fit: cover;
}

.sv-video-label {
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 6px;
  text-align: center;
}

.sv-success {
  color: #38a169;
  font-weight: 600;
}

.sv-fail {
  color: #e53e3e;
  font-weight: 600;
}

/* Controls */
.sv-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 20px;
}

.sv-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 18px;
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
}

.sv-btn:hover {
  background: var(--accent-hover);
}

.sv-btn-small {
  background: var(--section-bg);
  color: var(--text);
  border: 1px solid var(--card-border);
  padding: 5px 12px;
  font-size: 0.8rem;
  min-width: 44px;
}

.sv-btn-small:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--section-bg);
}

.sv-step-label {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
  min-width: 100px;
}

/* SVG Charts */
.sv-charts {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 12px;
}

.sv-chart-wrapper {
  flex: 1;
  max-width: 320px;
}

.sv-chart {
  width: 100%;
  height: auto;
}

.sv-baseline-path {
  fill: none;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.sv-steered-path {
  fill: none;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 8 4;
}

.sv-cursor-line {
  stroke: #333;
  stroke-width: 1.5;
  stroke-dasharray: 3 2;
  pointer-events: none;
}

.sv-onset-line {
  stroke: #999;
  stroke-width: 1;
  stroke-dasharray: 4 3;
}

.sv-onset-label {
  font-size: 8px;
  fill: #999;
  font-family: var(--font);
}

.sv-tick-label {
  font-size: 8px;
  fill: #888;
  font-family: var(--font);
}

.sv-chart-title {
  font-size: 11px;
  font-weight: 600;
  fill: var(--text);
  font-family: var(--font);
}

.sv-scrub-overlay {
  fill: transparent;
  cursor: crosshair;
  pointer-events: all;
}

/* Legend */
.sv-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
  padding: 10px 16px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  background: var(--card-bg);
}

.sv-legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.sv-legend-note {
  font-style: italic;
  font-size: 0.75rem;
}

/* ============================================================
   Responsive: Steering Visualization
   ============================================================ */

@media (max-width: 900px) {
  .sv-video-pair {
    flex-direction: column;
    align-items: center;
  }

  .sv-charts {
    flex-direction: column;
    align-items: center;
  }

  .sv-chart-wrapper {
    max-width: 100%;
    width: 100%;
  }
}

@media (max-width: 480px) {
  .sv-video-col video {
    width: 180px;
    height: 180px;
  }
}

/* ============================================================
   Per-Token Heatmap Visualization (pt-*)
   Reuses .image-strip, .heatmap-* from activation-viz.
   Only adds separator, normalize toggle, cursor line,
   and wider labels with token name + feature ID split.
   ============================================================ */

#per-token-viz {
  min-height: 200px;
}

/* Wider labels for per-token viz (token name + feature ID) */
#per-token-viz .heatmap-label.pt-label {
  width: 110px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  text-align: left;
  padding-right: 8px;
}

.pt-token-name {
  color: var(--text);
  font-weight: 700;
  white-space: nowrap;
}

.pt-fid {
  font-weight: 600;
  font-size: 0.7rem;
  white-space: nowrap;
}

/* Align image strip and separator with the wider labels */
#per-token-viz .image-strip {
  margin-left: 110px;
}

/* Separator between image and text token heatmap groups */
.pt-sep {
  height: 1px;
  background: var(--card-border);
  margin: 6px 0 6px 110px;
}

/* Normalize toggle */
.pt-normalize {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 8px;
}

.pt-normalize label {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}

.pt-normalize input[type="checkbox"] {
  accent-color: var(--accent);
}

/* Responsive per-token overrides */
@media (max-width: 900px) {
  #per-token-viz .heatmap-label.pt-label {
    width: 90px;
  }
  #per-token-viz .image-strip {
    margin-left: 90px;
  }
  .pt-sep {
    margin-left: 90px;
  }
}

@media (max-width: 480px) {
  #per-token-viz .heatmap-label.pt-label {
    width: 70px;
    font-size: 0.65rem;
    padding-right: 4px;
  }
  #per-token-viz .image-strip {
    margin-left: 70px;
  }
  .pt-sep {
    margin-left: 70px;
  }
  .pt-fid {
    font-size: 0.6rem;
  }
}

/* ============================================================
   Manual Token-Feature Heatmap (mh-*)
   ============================================================ */

#manual-heatmap-viz {
  min-height: 200px;
}

/* Wider labels for manual heatmap (token name + feature ID) */
#manual-heatmap-viz .heatmap-label.mh-label {
  width: 110px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  text-align: left;
  padding-right: 8px;
}

.mh-token-name {
  color: var(--text);
  font-weight: 700;
  white-space: nowrap;
}

.mh-fid {
  font-weight: 600;
  font-size: 0.7rem;
  white-space: nowrap;
}

/* Align image strip and separator with the wider labels */
#manual-heatmap-viz .image-strip.mh-image-strip {
  margin-left: 110px;
}

/* Separator between feature groups */
.mh-sep {
  height: 1px;
  background: var(--card-border);
  margin: 6px 0 6px 110px;
}

/* Normalize toggle */
.mh-normalize {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 8px;
}

.mh-normalize label {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}

.mh-normalize input[type="checkbox"] {
  accent-color: var(--accent);
}

/* Responsive manual heatmap overrides */
@media (max-width: 900px) {
  #manual-heatmap-viz .heatmap-label.mh-label {
    width: 90px;
  }
  #manual-heatmap-viz .image-strip.mh-image-strip {
    margin-left: 90px;
  }
  .mh-sep {
    margin-left: 90px;
  }
}

@media (max-width: 480px) {
  #manual-heatmap-viz .heatmap-label.mh-label {
    width: 70px;
    font-size: 0.65rem;
    padding-right: 4px;
  }
  #manual-heatmap-viz .image-strip.mh-image-strip {
    margin-left: 70px;
  }
  .mh-sep {
    margin-left: 70px;
  }
  .mh-fid {
    font-size: 0.6rem;
  }
}