:root {
  --ink: #1f2328;
  --ink-secondary: #4b5563;
  --ink-muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: #eff4ff;
  --surface: #ffffff;
  --surface-alt: #f6f8fa;
  --border: #e5e7eb;
  --col: 840px;
  --col-wide: 1040px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Noto Sans", "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--surface);
}

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

/* ── hero ─────────────────────────────────────────── */
.hero {
  max-width: var(--col);
  margin: 0 auto;
  padding: 56px 20px 8px;
  text-align: center;
}

.title {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(1.5rem, 3.4vw, 2.15rem);
  font-weight: 700;
  line-height: 1.28;
  margin: 0 0 22px;
}

.authors {
  font-size: 1.15rem;
  margin: 0 0 2px;
}

.author { color: var(--accent); font-weight: 600; }

.affiliation {
  font-size: 1.02rem;
  color: var(--ink-secondary);
  margin: 0 0 4px;
}

.venue {
  font-size: 0.95rem;
  color: var(--ink-muted);
  margin: 0 0 26px;
}

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 18px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.15s ease;
}

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


/* ── sections ─────────────────────────────────────── */
main {
  max-width: var(--col);
  margin: 0 auto;
  padding: 8px 20px 40px;
}

section { margin: 40px 0; }

h2 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.5rem;
  font-weight: 700;
  text-align: center;
  margin: 0 0 18px;
}

h3 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.1rem;
  font-weight: 700;
  margin: 30px 0 10px;
}

.abstract {
  margin: 0;
  text-align: justify;
  color: var(--ink-secondary);
}

.section-note {
  text-align: center;
  color: var(--ink-secondary);
  max-width: 660px;
  margin: -6px auto 20px;
  font-size: 0.98rem;
}

/* sections that need more room than the reading column */
.wide {
  max-width: var(--col-wide);
  margin-left: calc((var(--col) - var(--col-wide)) / 2);
  margin-right: calc((var(--col) - var(--col-wide)) / 2);
}

/* ── key results ──────────────────────────────────── */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.stat {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 16px;
  text-align: center;
}

.stat-number {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 6px;
}

.stat p {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--ink-secondary);
}

/* ── method diagram ───────────────────────────────── */
.diagram { margin: 0; }

.diagram-scroll { overflow-x: auto; }

.diagram svg {
  width: 100%;
  height: auto;
  display: block;
}

.diagram figcaption {
  max-width: 760px;
  margin: 14px auto 0;
}

/* ── tables ───────────────────────────────────────── */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 10px;
}

table {
  border-collapse: collapse;
  width: 100%;
  min-width: 560px;
  font-size: 0.88rem;
  background: var(--surface);
}

caption {
  caption-side: top;
  text-align: left;
  font-size: 0.9rem;
  color: var(--ink-muted);
  padding: 0 0 8px;
}

th, td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

thead th {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.92rem;
  background: var(--surface-alt);
  white-space: nowrap;
}

tbody tr:last-child td { border-bottom: 0; }

td.num, th.num {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

tbody th {
  font-weight: 600;
  color: var(--ink-secondary);
  white-space: nowrap;
  vertical-align: top;
  background: var(--surface-alt);
}

td.hl, th.hl {
  background: var(--accent-soft);
  font-weight: 600;
  color: var(--ink);
}

tr.group-start td, tr.group-start th { border-top: 2px solid var(--border); }

.table-note {
  font-size: 0.85rem;
  color: var(--ink-muted);
  margin: 10px 2px 0;
}

/* ── figures ──────────────────────────────────────── */
.fig-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.fig-grid figure, .fig-wide { margin: 0; }

/* keep captions on one baseline when paired images differ in height */
.fig-grid figure {
  display: flex;
  flex-direction: column;
}

.fig-grid figcaption { margin-top: auto; padding-top: 8px; }

.fig-grid img, .fig-wide img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}

.fig-wide + .fig-wide { margin-top: 24px; }

figcaption {
  font-size: 0.92rem;
  color: var(--ink-muted);
  text-align: center;
  margin-top: 8px;
}

/* ── tabs ─────────────────────────────────────────── */
.tabs {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-bottom: 18px;
}

.tab-btn {
  border: 1px solid var(--border);
  background: var(--surface-alt);
  color: var(--ink-secondary);
  font: inherit;
  font-size: 0.92rem;
  font-weight: 600;
  padding: 7px 20px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.tab-btn:hover { color: var(--ink); }

.tab-btn[aria-selected="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ── bibtex ───────────────────────────────────────── */
.bibtex {
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.55;
  margin: 0;
}

/* ── footer ───────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--ink-muted);
  font-size: 0.88rem;
  padding: 22px 20px 30px;
  margin-top: 20px;
}

footer p { margin: 0; }

/* ── method diagram internals ─────────────────────── */
.diagram svg text {
  font-family: "Noto Sans", "Helvetica Neue", Arial, sans-serif;
}

.dg-box {
  fill: var(--surface-alt);
  stroke: var(--border);
  stroke-width: 1.5;
}

.dg-box-accent {
  fill: var(--accent-soft);
  stroke: var(--accent);
}

.dg-badge { fill: var(--accent); }
.dg-badge-t { fill: #fff; font-size: 12px; font-weight: 700; }

.dg-title { fill: var(--ink); font-size: 15px; font-weight: 600; }
.dg-sub { fill: var(--ink-secondary); font-size: 13px; }
.dg-label { fill: var(--ink-muted); font-size: 13px; }

.dg-chip { fill: var(--surface); stroke: var(--accent); stroke-width: 1.2; }
.dg-chip-t { fill: var(--ink); font-size: 12.5px; font-weight: 600; }

.dg-arrow {
  fill: none;
  stroke: var(--ink-muted);
  stroke-width: 1.8;
  marker-end: url(#ah);
}

.dg-dash { stroke-dasharray: 6 5; }
.dg-head { fill: var(--ink-muted); }

/* ── spacing helpers ──────────────────────────────── */
.fig-grid-spaced { margin-top: 24px; }
.table-wrap-spaced { margin-top: 26px; }

[hidden] { display: none !important; }

/* ── responsive ───────────────────────────────────── */
@media (max-width: 1120px) {
  .wide { max-width: 100%; margin-left: 0; margin-right: 0; }
}

@media (max-width: 720px) {
  .fig-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .hero { padding-top: 36px; }
  body { font-size: 16px; }
  .abstract { text-align: left; }
  .tabs { flex-wrap: wrap; }
  .diagram svg { min-width: 760px; }
}