:root {
  --ink: #16181d;
  --muted: #5c6270;
  --faint: #9a9fa8;
  --line: #e6e8ec;
  --bg: #ffffff;
  --bg-alt: #f6f7fa;
  --accent: #2455a4;
  --accent-dark: #173868;
  --red: #ab241c;
  --red-soft: #f6e7e5;
  --purple: #6656a3;

  --serif: "Source Serif 4", "Noto Serif", Georgia, serif;
  --sans: "Inter", "Noto Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --display: "Space Grotesk", var(--sans);
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  --content: 860px;
  --wide: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s ease, color 0.15s ease;
}
a:hover { border-bottom-color: currentColor; }

.wrap {
  max-width: var(--content);
  margin: 0 auto;
  padding: 0 28px;
}
.wrap-wide {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 28px;
}

section { padding: 68px 0; }
section + section { border-top: 1px solid var(--line); }

.eyebrow {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 14px;
  text-align: center;
}

h1, h2, h3 { font-family: var(--display); color: var(--ink); font-weight: 600; margin: 0; }

.section-title {
  font-size: 27px;
  text-align: center;
  max-width: 720px;
  margin: 0 auto 34px;
  line-height: 1.3;
}

.section-lede {
  text-align: center;
  color: var(--muted);
  max-width: 620px;
  margin: -20px auto 36px;
  font-size: 16px;
}

/* ---------- Hero ---------- */
.hero {
  padding: 84px 0 40px;
  text-align: center;
}
.venue-line {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 22px;
}
.venue-line .sep { color: var(--faint); margin: 0 8px; }

.title {
  font-family: var(--display);
  font-size: clamp(28px, 4.2vw, 44px);
  line-height: 1.18;
  font-weight: 600;
  letter-spacing: -0.01em;
  max-width: 880px;
  margin: 0 auto;
}

.authors {
  margin: 30px auto 6px;
  font-size: 17.5px;
  max-width: 760px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}
.authors .author { white-space: nowrap; }
.authors .sep { color: var(--faint); margin: 0 10px; }
.authors a { color: var(--ink); border-bottom: 1px solid var(--line); }
.authors a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.authors sup { color: var(--accent); font-size: 0.65em; }

.affiliations {
  color: var(--muted);
  font-size: 14.5px;
  margin-top: 10px;
}
.affiliations sup { color: var(--accent); margin-right: 2px; }

.venue-meta {
  color: var(--faint);
  font-size: 13.5px;
  margin-top: 18px;
}

/* ---------- Resource buttons ---------- */
.buttons-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin: 34px 0 8px;
}
.resource-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-family: var(--sans);
  font-size: 14.5px;
  font-weight: 500;
  border: 1px solid var(--ink);
}
.resource-btn:hover {
  background: #fff;
  color: var(--ink);
  border-bottom: 1px solid var(--ink);
}
.resource-btn svg { width: 15px; height: 15px; flex: none; }
.resource-btn.ghost {
  background: #fff;
  color: var(--ink);
}
.resource-btn.ghost:hover { background: var(--ink); color: #fff; }

.doi-line {
  text-align: center;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--faint);
  margin-top: 20px;
}
.doi-line a { color: var(--muted); }

/* ---------- Abstract ---------- */
.abstract p {
  font-size: 17px;
  color: #2b2e35;
}
.abstract strong { color: var(--ink); }

/* ---------- Figure ---------- */
.figure-card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px;
  background: var(--bg-alt);
}
.figure-card img { border-radius: 4px; }
.figure-caption {
  text-align: center;
  color: var(--muted);
  font-size: 14.5px;
  max-width: 700px;
  margin: 22px auto 0;
}

/* ---------- Big stat ---------- */
.stat-block { text-align: center; }
.stat-number {
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(64px, 12vw, 128px);
  line-height: 1;
  color: var(--red);
  letter-spacing: -0.02em;
}
.stat-caption {
  font-size: 18px;
  max-width: 560px;
  margin: 16px auto 0;
  color: var(--ink);
}
.stat-caption strong { color: var(--red); }

.collapse-defs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  max-width: 700px;
  margin: 40px auto 0;
}
.collapse-defs .def {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px 18px;
  font-size: 14.5px;
  color: var(--muted);
  text-align: left;
}
.collapse-defs .def strong { color: var(--ink); display: block; margin-bottom: 4px; font-family: var(--mono); font-size: 13px; letter-spacing: 0.03em;}

.callout {
  max-width: 640px;
  margin: 40px auto 0;
  text-align: center;
  font-family: var(--serif);
  font-style: italic;
  font-size: 18px;
  color: var(--ink);
  padding: 20px 26px;
  border-left: 3px solid var(--red);
  background: var(--red-soft);
  border-radius: 0 8px 8px 0;
  text-align: left;
}

.chart-wrap { max-width: 760px; margin: 0 auto; }
.chart-wrap img { margin: 0 auto; }

/* ---------- Model suite ---------- */
.model-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  max-width: 640px;
  margin: 0 auto 36px;
  font-size: 14.5px;
}
.model-col-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 10px;
  display: block;
}
.model-col-label.gcn { color: var(--accent); }
.model-col-label.tf { color: var(--purple); }
.model-list { list-style: none; margin: 0; padding: 0; }
.model-list li {
  padding: 6px 0;
  border-bottom: 1px dashed var(--line);
  color: var(--ink);
}
.model-list li:last-child { border-bottom: none; }

.finding-line {
  text-align: center;
  max-width: 640px;
  margin: 30px auto 0;
  font-size: 16px;
  color: var(--muted);
}
.finding-line strong { color: var(--ink); }

/* ---------- Data diversity ---------- */
.diversity-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 44px;
  flex-wrap: wrap;
  margin: 8px 0 30px;
}
.diversity-stat {
  text-align: center;
}
.diversity-stat .n {
  font-family: var(--display);
  font-weight: 600;
  font-size: 46px;
  color: var(--accent);
}
.diversity-stat .l {
  font-size: 13.5px;
  color: var(--muted);
  margin-top: 4px;
}
.warning-note {
  max-width: 620px;
  margin: 0 auto;
  font-size: 15px;
  color: var(--muted);
  text-align: center;
  padding: 14px 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-alt);
}
.warning-note strong { color: var(--ink); }

/* ---------- BibTeX ---------- */
.bibtex-box {
  position: relative;
  background: #0f1115;
  border-radius: 10px;
  padding: 24px 24px;
  max-width: var(--wide);
}
.bibtex-box pre {
  margin: 0;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
  color: #d7dae0;
}
.copy-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  font-family: var(--sans);
  font-size: 12.5px;
  color: #d7dae0;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: 999px;
  padding: 6px 14px;
  cursor: pointer;
}
.copy-btn:hover { background: rgba(255,255,255,0.16); }

/* ---------- Footer ---------- */
footer {
  padding: 40px 0 56px;
  text-align: center;
  color: var(--faint);
  font-size: 13px;
}
footer .venue { color: var(--muted); font-family: var(--mono); margin-bottom: 6px; }

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
  section { padding: 48px 0; }
  .hero { padding: 56px 0 28px; }
  .model-grid { grid-template-columns: 1fr; gap: 24px; }
  .collapse-defs { grid-template-columns: 1fr; }
  .diversity-row { gap: 24px; }
  .bibtex-box { padding: 44px 16px 20px; }
  .copy-btn { top: 12px; right: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

a:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}