/* ============================================================
   Multimodal AI Landscape — shared design system
   ============================================================ */

/* ── Design tokens ──────────────────────────────────────── */
:root {
  --accent:        #1a56db;
  --accent-hover:  #1648c0;
  --accent-light:  #eef2ff;
  --bg:            #f0f4f8;
  --surface:       #ffffff;
  --border:        #e2e8f0;
  --border-strong: #cbd5e1;
  --text-primary:  #0f172a;
  --text-secondary:#334155;
  --text-muted:    #64748b;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 2px 6px rgba(0,0,0,.04);
  --shadow-md: 0 2px 6px rgba(0,0,0,.06), 0 8px 20px rgba(0,0,0,.06);
  --shadow-lg: 0 4px 12px rgba(0,0,0,.08), 0 16px 40px rgba(0,0,0,.08);
  --radius:    12px;
  --radius-sm: 8px;
  --nav-h:     60px;
  --topbar-h:  48px;
  --sub-nav-h: 44px;
  --max-w:     1280px;
  --max-w-wide:1600px;
  --gap:       16px;
}

/* ── Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { display: block; }

/* ── Container ──────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
@media (max-width: 600px) { .container { padding: 0 16px; } }

/* ── Navigation ─────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(255,255,255,.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 14.5px;
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
  letter-spacing: -0.01em;
}
.nav-logo:hover { text-decoration: none; }
.nav-logo-mark {
  width: 32px;
  height: 32px;
  background: var(--accent);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: 14px;
  flex-shrink: 0;
}
.nav-logo-img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  border-radius: 6px;
  flex-shrink: 0;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}
.nav-links a {
  display: block;
  padding: 6px 12px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 6px;
  transition: color .15s, background .15s;
  text-decoration: none;
  white-space: nowrap;
}
.nav-links a:hover { color: var(--accent); background: var(--accent-light); text-decoration: none; }
.nav-links a.active { color: var(--accent); background: var(--accent-light); font-weight: 600; }
.nav-github {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-left: 6px;
  transition: border-color .15s, color .15s;
  text-decoration: none;
}
.nav-github:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text-secondary);
  border-radius: 6px;
  line-height: 0;
}
.nav-hamburger:hover { background: var(--bg); }
.nav-mobile-menu {
  display: none;
  position: absolute;
  top: var(--nav-h);
  left: 0; right: 0;
  background: white;
  border-bottom: 1px solid var(--border);
  padding: 10px 24px 16px;
  box-shadow: var(--shadow-md);
  z-index: 99;
}
.nav-mobile-menu.open { display: block; }
.nav-mobile-menu a {
  display: block;
  padding: 10px 0;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
  text-decoration: none;
}
.nav-mobile-menu a:last-child { border-bottom: none; }
.nav-mobile-menu a.active { color: var(--accent); }
@media (max-width: 780px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
}

/* ── Page hero ──────────────────────────────────────────── */
.page-hero {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 52px 0 44px;
}
.page-hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--accent);
  background: var(--accent-light);
  border: 1px solid rgba(26,86,219,.15);
  border-radius: 999px;
  padding: 4px 12px;
  margin-bottom: 18px;
}
.page-hero h1 {
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -.025em;
  color: var(--text-primary);
  margin-bottom: 16px;
}
.page-hero-lead {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.75;
  max-width: 780px;
  margin-bottom: 4px;
}
.page-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 22px;
  font-size: 13px;
  color: var(--text-muted);
}
.page-hero-meta span {
  display: flex;
  align-items: center;
  gap: 5px;
}
.page-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}

/* ── Main content ───────────────────────────────────────── */
.page-main {
  padding: 36px 0 72px;
  flex: 1;
}

/* ── Stats strip ────────────────────────────────────────── */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
  margin-bottom: 44px;
}
@media (max-width: 760px) { .stats-strip { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 420px) { .stats-strip { grid-template-columns: 1fr; } }
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px 18px;
  box-shadow: var(--shadow-sm);
}
.stat-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-muted);
  margin-bottom: 7px;
}
.stat-value {
  font-size: 30px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -.025em;
  line-height: 1;
}
.stat-sub {
  font-size: 12.5px;
  color: var(--text-muted);
  margin-top: 5px;
  line-height: 1.4;
}

/* ── Section heading ────────────────────────────────────── */
.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.section-heading h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -.01em;
}
.section-link {
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  white-space: nowrap;
  text-decoration: none;
}
.section-link:hover { text-decoration: underline; }

/* ── Grid layouts ───────────────────────────────────────── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap);
  align-items: stretch;
}
@media (max-width: 920px) { .grid-2 { grid-template-columns: 1fr; } }

/* ── Card ───────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: box-shadow .2s;
}
.card:hover { box-shadow: var(--shadow-md); }

.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  padding: 13px 16px 12px;
  border-bottom: 1px solid var(--border);
  background: #fafbfc;
  border-radius: var(--radius) var(--radius) 0 0;
}
.card-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .06em;
  line-height: 1.4;
}
.card-title-full {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: none;
  letter-spacing: 0;
  line-height: 1.4;
}
.card-actions {
  display: flex;
  align-items: center;
  gap: 5px;
  flex-shrink: 0;
}
.card-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 5px;
  cursor: pointer;
  transition: color .15s, border-color .15s;
  white-space: nowrap;
  line-height: 1.6;
}
.card-action-btn:hover { color: var(--accent); border-color: var(--accent); }

/* ── Help tooltip ───────────────────────────────────────── */
.help-tip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #e2e8f0;
  color: var(--text-muted);
  font-size: 10px;
  font-weight: 700;
  cursor: help;
  flex-shrink: 0;
  position: relative;
  vertical-align: middle;
  margin-left: 4px;
}
.help-tip::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: #1e293b;
  color: #f1f5f9;
  font-size: 12px;
  font-weight: 400;
  line-height: 1.55;
  padding: 8px 12px;
  border-radius: 6px;
  white-space: normal;
  width: max-content;
  max-width: 240px;
  pointer-events: none;
  opacity: 0;
  transition: opacity .15s;
  z-index: 200;
  text-transform: none;
  letter-spacing: 0;
  font-style: normal;
  box-shadow: 0 4px 12px rgba(0,0,0,.25);
}
.help-tip:hover::after,
.help-tip:focus-visible::after { opacity: 1; }

/* ── Card controls row ──────────────────────────────────── */
.card-controls {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-wrap: wrap;
  padding: 10px 14px 4px;
}

/* ── Chart container ────────────────────────────────────── */
.chart-wrap {
  flex-grow: 1;
  min-height: 460px;
  position: relative;
}

/* ── Figure caption ─────────────────────────────────────── */
.card-caption {
  padding: 10px 16px 14px;
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
  border-top: 1px solid var(--border);
  font-style: italic;
}

/* ── Loading skeleton ───────────────────────────────────── */
.skeleton-wrap {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: flex-end;
  gap: 12px;
  padding: 24px 28px 32px;
  background: white;
  z-index: 5;
}
.skeleton {
  flex: 1;
  border-radius: 4px;
  background: linear-gradient(90deg, #f0f4f8 25%, #e2e8f0 50%, #f0f4f8 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
}
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position:  200% 0; }
}

/* ── Error panel ────────────────────────────────────────── */
.chart-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 200px;
  color: #dc2626;
  font-size: 13.5px;
  text-align: center;
  padding: 32px 24px;
  line-height: 1.5;
}

/* ── Chips ──────────────────────────────────────────────── */
.chips-group {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 12px;
  background: var(--surface);
  font-size: 12.5px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background .15s, color .15s, border-color .15s, box-shadow .15s;
  line-height: 1.5;
  user-select: none;
}
.chip:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.chip:hover:not(.active) {
  background: var(--accent-light);
  border-color: var(--accent);
  color: var(--accent);
}
.chip.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  box-shadow: 0 1px 4px rgba(26,86,219,.2);
}
.chip-clear { background: #f8fafc; color: var(--text-muted); }
.chip-more  { background: #f5f7fa; color: var(--text-secondary); }

/* ── Select control ─────────────────────────────────────── */
.select-wrap {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-left: auto;
  flex-shrink: 0;
}
.select-wrap select {
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  font-size: 13px;
  color: var(--text-primary);
  cursor: pointer;
  outline: none;
}
.select-wrap select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(26,86,219,.1);
}

/* ── Year label (chart 5) ───────────────────────────────── */
.year-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  margin-right: 2px;
}

/* ── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: .15s;
  border: none;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); color: white; text-decoration: none; }
.btn-secondary {
  background: var(--surface);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn-sm { padding: 6px 14px; font-size: 12.5px; }

/* ── Explore sub-nav ────────────────────────────────────── */
.sub-nav {
  position: sticky;
  top: var(--nav-h);
  z-index: 50;
  background: rgba(255,255,255,.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  height: var(--sub-nav-h);
}
.sub-nav-inner {
  display: flex;
  align-items: stretch;
  height: 100%;
}

/* ── Collapsible toggle (visible only on mobile/tablet) ── */
.sub-nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 0 16px;
  height: var(--sub-nav-h);
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  transition: color .15s;
  white-space: nowrap;
}
.sub-nav-toggle:hover { color: var(--accent); }
.sub-nav-toggle-icon { display: flex; align-items: center; }
.sub-nav-toggle-text { flex: 1; text-align: left; }
.sub-nav-chevron {
  margin-left: auto;
  transition: transform .25s ease;
  flex-shrink: 0;
}
.sub-nav.open .sub-nav-chevron { transform: rotate(180deg); }

/* ── Sub-nav panel (links container) ─────────────────── */
.sub-nav-panel {
  display: flex;
  align-items: stretch;
  flex: 1;
  overflow-x: auto;
  scrollbar-width: none;
  height: 100%;
}
.sub-nav-panel::-webkit-scrollbar { display: none; }

.sub-nav-link {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 0 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  border-bottom: 2px solid transparent;
  white-space: nowrap;
  transition: color .15s, border-color .15s;
  text-decoration: none;
  flex-shrink: 0;
}
.sub-nav-link:hover { color: var(--accent); text-decoration: none; }
.sub-nav-link.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.sub-nav-reset {
  display: flex;
  align-items: center;
  gap: 5px;
  margin-left: auto;
  flex-shrink: 0;
  padding: 0 16px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  background: none;
  border: none;
  border-left: 1px solid var(--border);
  cursor: pointer;
  transition: color .15s;
}
.sub-nav-reset:hover { color: var(--accent); }

/* ── Explore sections ───────────────────────────────────── */
.explore-section {
  scroll-margin-top: calc(var(--nav-h) + var(--sub-nav-h) + 20px);
  margin-bottom: 44px;
}
.explore-section:last-child { margin-bottom: 0; }

/* ── Prose ──────────────────────────────────────────────── */
.prose { max-width: 740px; }
.prose h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin: 40px 0 14px;
  letter-spacing: -.01em;
}
.prose h2:first-child { margin-top: 0; }
.prose h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 28px 0 10px;
}
.prose p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}
.prose ul, .prose ol {
  margin: 0 0 16px 22px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
}
.prose li { margin-bottom: 6px; }
.prose strong { color: var(--text-primary); font-weight: 600; }
.prose a { color: var(--accent); }

/* ── Notice / callout ───────────────────────────────────── */
.notice {
  display: flex;
  gap: 12px;
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  line-height: 1.65;
  margin: 20px 0;
}
.notice svg { flex-shrink: 0; margin-top: 2px; }
.notice-info    { background: #eff6ff; border: 1px solid #bfdbfe; color: #1e40af; }
.notice-warning { background: #fffbeb; border: 1px solid #fde68a; color: #92400e; }
.notice-neutral { background: #f8fafc; border: 1px solid var(--border); color: var(--text-secondary); }

/* ── Citation blocks ────────────────────────────────────── */
.citation-block {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 18px 22px;
  margin: 16px 0;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
}
.bibtex-wrap { position: relative; }
.bibtex-header {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 10px;
}
.bibtex-label {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-primary);
}
.bibtex-hint {
  font-size: 12px;
  color: var(--text-muted);
}
.bibtex-block {
  position: relative;
  background: #1b2536;
  color: #e2e8f0;
  border-radius: 8px;
  padding: 22px 24px;
  font-family: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', Consolas, monospace;
  font-size: 12.5px;
  line-height: 1.75;
  overflow-x: auto;
  white-space: pre;
  border: 1px solid rgba(255,255,255,.06);
  box-shadow: 0 2px 8px rgba(0,0,0,.12);
}
.bibtex-copy-btn {
  position: absolute;
  top: 14px; right: 14px;
  padding: 5px 12px;
  font-size: 11px;
  font-weight: 600;
  color: #94a3b8;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 5px;
  cursor: pointer;
  transition: background .15s, color .15s, border-color .15s;
  letter-spacing: .03em;
}
.bibtex-copy-btn:hover {
  background: rgba(255,255,255,.16);
  color: #fff;
  border-color: rgba(255,255,255,.25);
}

/* ── Footer citation layout ─────────────────────────────── */
.footer-citation-section {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
  padding: 52px 0 44px;
  align-items: start;
}
.footer-cite-info .nav-logo { margin-bottom: 16px; }
.footer-cite-info p {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.75;
  max-width: 340px;
}
.footer-cite-bibtex { min-width: 0; }
.footer-cite-bibtex .bibtex-block {
  white-space: pre-wrap;
  word-break: break-word;
}

/* ── Citation strip (compact, used in footer) ───────────── */
.citation-strip {
  background: var(--accent-light);
  border: 1px solid rgba(26,86,219,.15);
  border-radius: var(--radius-sm);
  padding: 13px 16px;
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.65;
}
.citation-strip strong {
  display: block;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 5px;
}

/* ── Disclaimer banner ──────────────────────────────────── */
.disclaimer {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 13px;
  color: #78350f;
  line-height: 1.6;
  margin-bottom: 28px;
  display: flex;
  gap: 10px;
  align-items: flex-start;
}
.disclaimer svg { flex-shrink: 0; margin-top: 1px; }

/* ── Footer ─────────────────────────────────────────────── */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  margin-top: auto;
}
.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 36px;
  padding: 52px 0 44px;
}
@media (max-width: 900px) { .footer-top { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .footer-top { grid-template-columns: 1fr; gap: 28px; } }
.footer-brand p {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.75;
  margin-top: 12px;
  max-width: 280px;
}
.footer-col h4 {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--text-muted);
  margin-bottom: 14px;
}
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 9px; }
.footer-col ul a {
  font-size: 13.5px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color .15s;
}
.footer-col ul a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 16px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}
.footer-bottom-text {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
}
.footer-bottom-text a { color: var(--text-muted); }
.footer-bottom-text a:hover { color: var(--accent); }
.footer-bottom-links {
  display: flex;
  gap: 16px;
}
.footer-bottom-links a {
  font-size: 12px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color .15s;
}
.footer-bottom-links a:hover { color: var(--accent); }

/* ── Utility classes ────────────────────────────────────── */
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.mt-sm  { margin-top: 8px; }
.mt-md  { margin-top: 16px; }
.mt-lg  { margin-top: 28px; }
.mt-xl  { margin-top: 40px; }
.mb-sm  { margin-bottom: 8px; }
.mb-md  { margin-bottom: 16px; }
.mb-lg  { margin-bottom: 28px; }
.flex   { display: flex; }
.items-center { align-items: center; }
.gap-sm { gap: 8px; }
.gap-md { gap: 12px; }
.text-muted { color: var(--text-muted); }
.text-sm    { font-size: 13px; }

/* ── Multi-dataset stats section ────────────────────────── */
.stats-section { margin-bottom: 8px; }
.stats-section-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .09em;
  color: var(--text-muted);
  margin: 20px 0 8px;
}
.stats-section-title:first-child { margin-top: 0; }

/* ── Chart "not available" panel ────────────────────────── */
.chart-unavailable {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 40px 32px;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}
.chart-unavailable svg { flex-shrink: 0; opacity: 0.45; }

/* ── Dataset selector (explore page, >1 dataset) ─────────── */
.dataset-selector {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  flex-wrap: wrap;
}
.dataset-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .07em;
  flex-shrink: 0;
}
.dataset-selector .chip { text-decoration: none; }

/* ============================================================
   ONE-PAGE DASHBOARD LAYOUT
   ============================================================ */

/* ── Wide container (replaces .container on the dashboard) ── */
.container-wide {
  max-width: var(--max-w-wide);
  margin: 0 auto;
  padding: 0 clamp(16px, 3vw, 48px);
}

/* ── Compact top bar (replaces full site-nav on dashboard) ── */
.site-topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--topbar-h);
  background: rgba(255,255,255,.97);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.topbar-links {
  display: flex;
  align-items: center;
  gap: 2px;
}
.topbar-link {
  display: block;
  padding: 5px 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 6px;
  transition: color .15s, background .15s;
  text-decoration: none;
  white-space: nowrap;
}
.topbar-link:hover {
  color: var(--accent);
  background: var(--accent-light);
  text-decoration: none;
}
.topbar-github {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  margin-left: 6px;
  transition: border-color .15s, color .15s;
  text-decoration: none;
}
.topbar-github:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* ── Dashboard hero / intro section ─────────────────────── */
.dashboard-hero {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 40px 0 36px;
}
.hero-content {
  max-width: 100%;
}
.hero-content h1 {
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.03em;
  color: var(--text-primary);
  margin-bottom: 18px;
}
.hero-body {
  font-size: 15.5px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 10px;
}
.hero-body:last-of-type { margin-bottom: 0; }
.hero-body a { color: var(--accent); }
.hero-body-note {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 6px;
}
.hero-meta-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}
.meta-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  font-size: 12.5px;
  color: var(--text-muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  white-space: nowrap;
}
.meta-badge svg { flex-shrink: 0; }
.meta-badge-link {
  color: var(--accent);
  background: var(--accent-light);
  border-color: rgba(26,86,219,.15);
  text-decoration: none;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.meta-badge-link:hover {
  background: rgba(26,86,219,.12);
  border-color: var(--accent);
  text-decoration: none;
}

/* ── Stats band (between hero and sub-nav) ──────────────── */
.stats-band {
  background: var(--bg);
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

/* ── Sub-nav override for one-page layout ───────────────── */
.one-page .sub-nav {
  top: var(--topbar-h);
}
.one-page .explore-section {
  scroll-margin-top: calc(var(--topbar-h) + var(--sub-nav-h) + 24px);
}

/* ── Sub-nav pill style upgrade ─────────────────────────── */
.one-page .sub-nav-panel {
  gap: 4px;
  padding: 0 4px;
}
.one-page .sub-nav-link {
  border-bottom: none;
  border-radius: 6px;
  padding: 6px 14px;
  margin: 4px 0;
  transition: color .15s, background .15s;
}
.one-page .sub-nav-link:hover {
  background: var(--accent-light);
  color: var(--accent);
}
.one-page .sub-nav-link.active {
  background: var(--accent);
  color: #fff;
  border-bottom-color: transparent;
  font-weight: 600;
  box-shadow: 0 1px 4px rgba(26,86,219,.18);
}

/* ── Hide injected nav on one-page dashboard ────────────── */
.one-page .site-nav { display: none; }

/* ============================================================
   RESPONSIVE BREAKPOINTS
   ============================================================ */

/* ── Wide desktop (≥ 1440px) ────────────────────────────── */
@media (min-width: 1440px) {
  .chart-wrap { min-height: 520px; }
  .footer-citation-section {
    grid-template-columns: 1fr 3fr;
    gap: 64px;
  }
}

/* ── Tablet & narrow desktop (≤ 1023px) ─────────────────── */
@media (max-width: 1023px) {
  /* Collapsible sub-nav */
  .sub-nav-toggle { display: flex; }
  .one-page .sub-nav {
    height: auto;
    min-height: var(--sub-nav-h);
  }
  .one-page .sub-nav-inner {
    flex-direction: column;
  }
  .one-page .sub-nav-panel {
    display: none;
    flex-direction: column;
    align-items: stretch;
    height: auto;
    overflow: visible;
    gap: 2px;
    padding: 0 0 12px;
  }
  .one-page .sub-nav.open .sub-nav-panel {
    display: flex;
  }
  .one-page .sub-nav-link {
    padding: 10px 16px;
    font-size: 14px;
    margin: 0;
    height: auto;
    border-radius: 8px;
  }
  .one-page .sub-nav-reset {
    border-left: none;
    border-top: 1px solid var(--border);
    margin-top: 4px;
    padding: 10px 16px;
    justify-content: center;
  }

  /* Scroll offset: topbar + collapsed toggle + breathing room */
  .one-page .explore-section {
    scroll-margin-top: calc(var(--topbar-h) + var(--sub-nav-h) + 16px);
    margin-bottom: 32px;
  }

  /* Cards */
  .card-header { padding: 12px 14px 10px; flex-wrap: wrap; }
  .card-title { font-size: 11.5px; }
  .card-controls { padding: 8px 12px 4px; }
  .card-caption { font-size: 11.5px; }

  /* Chart */
  .chart-wrap { min-height: 380px; }

  /* Chips */
  .chip { padding: 5px 10px; font-size: 12px; }

  /* Footer citation */
  .footer-citation-section {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 0 36px;
  }
  .footer-cite-info p { max-width: 100%; }

  /* Footer bottom */
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 10px; }

  /* Bibtex */
  .bibtex-header { flex-direction: column; gap: 4px; }
}

/* ── Mobile (≤ 639px) ───────────────────────────────────── */
@media (max-width: 639px) {
  /* Topbar */
  .topbar-links { gap: 0; }
  .topbar-link { padding: 4px 6px; font-size: 12px; }
  .topbar-github { width: 28px; height: 28px; margin-left: 4px; }

  /* Hero */
  .dashboard-hero { padding: 28px 0 24px; }
  .hero-content h1 { font-size: 22px; }
  .hero-body { font-size: 14px; }
  .hero-meta-strip { gap: 8px; }
  .meta-badge { font-size: 11.5px; padding: 4px 10px; }

  /* Stats */
  .stats-band { padding: 14px 0; }
  .stat-card { padding: 14px; }
  .stat-value { font-size: 24px; }

  /* Sub-nav: bigger touch targets */
  .one-page .sub-nav-link {
    padding: 12px 16px;
    font-size: 14.5px;
  }

  /* Card actions stack */
  .card-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  .card-actions { width: 100%; }
  .card-caption { padding: 8px 14px 12px; }

  /* Chart */
  .chart-wrap { min-height: 300px; }

  /* Chips */
  .chips-group { gap: 5px; }
  .chip { padding: 5px 9px; font-size: 11.5px; }

  /* Select */
  .select-wrap { margin-left: 0; width: 100%; }

  /* Bibtex */
  .bibtex-block { font-size: 11px; padding: 16px 14px; }
}

/* ── Small mobile (≤ 479px) ─────────────────────────────── */
@media (max-width: 479px) {
  .topbar-link:not(:first-child):not(:last-child) { display: none; }

  /* Tighter container */
  .container-wide { padding: 0 12px; }
  .card { border-radius: 10px; }

  /* Hero */
  .hero-content h1 { font-size: 20px; }
  .hero-body { font-size: 13px; line-height: 1.7; }
  .hero-body-note { font-size: 12.5px; }
  .hero-meta-strip { flex-direction: column; align-items: flex-start; }

  /* Chart */
  .chart-wrap { min-height: 240px; }

  /* Footer */
  .footer-bottom-links { flex-direction: column; gap: 8px; }

  /* Bibtex */
  .bibtex-block { font-size: 10.5px; padding: 14px 12px; padding-right: 56px; }
  .bibtex-copy-btn { top: 10px; right: 8px; font-size: 10px; padding: 4px 8px; }
}