:root {
  --accent: #b5121b;      /* contest red */
  --accent-soft: #e08a2e; /* warm amber */
  --ink: #1c1c22;
  --muted: #6b6b76;
  --line: #e7e7ec;
  --tint: #f7f7fa;
  /* unified card system — used everywhere so sections feel like one page */
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 8px 24px rgba(20, 20, 40, 0.05);
  --shadow-lg: 0 14px 32px rgba(20, 20, 40, 0.09);
}

/* One card language for every panel on the page */
.box {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

html { scroll-behavior: smooth; scroll-padding-top: 4rem; }

body {
  color: var(--ink);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

/* fancy section headers: gradient icon badge + large title + accent underline */
.section-head {
  display: flex; align-items: center; justify-content: center;
  gap: 0.8rem; margin-bottom: 1.2rem; flex-wrap: wrap;
}
.section-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; border-radius: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent-soft));
  color: #fff; font-size: 1.3rem;
  box-shadow: 0 10px 22px rgba(181,18,27,0.28);
}
.section-title {
  position: relative; margin: 0; color: var(--ink);
  font-size: 2.15rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.12;
}
.section-title::after {
  content: "";
  display: block;
  width: 58px; height: 3px;
  margin: 0.55rem auto 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-soft));
  border-radius: 3px;
}
.section-sub { color: var(--muted); max-width: 720px; margin: 0.2rem auto 1.6rem; }

@media (max-width: 520px) {
  .section-icon { width: 40px; height: 40px; font-size: 1.1rem; }
  .section-title { font-size: 1.7rem; }
}
.has-bg-tint { background: var(--tint); }

/* ---------- nav ---------- */
.site-nav {
  background: rgba(255,255,255,0.92);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(0,0,0,0.02);
}
.brand-text { font-weight: 800; color: var(--accent); font-size: 1.15rem; }
.nav-link { color: var(--ink); font-weight: 500; }
.nav-link.is-current { color: var(--accent); }
.nav-link.is-current::after {
  content: ""; display: block; height: 2px; background: var(--accent);
  border-radius: 2px; margin-top: 2px;
}

/* ---------- hero ---------- */
.hero-vc {
  position: relative;
  padding: 6rem 1rem 3rem;
  overflow: hidden;
  background: linear-gradient(180deg, #fbfbfd 0%, #f3f3f7 100%);
  border-bottom: 1px solid var(--line);
}
.hero-bg {
  position: absolute; inset: 0;
  background-image:
    radial-gradient(circle at 20% 15%, rgba(181,18,27,0.07), transparent 40%),
    radial-gradient(circle at 82% 70%, rgba(224,138,46,0.08), transparent 42%),
    linear-gradient(rgba(0,0,0,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,0,0,0.025) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 28px 28px, 28px 28px;
  mask-image: radial-gradient(circle at 50% 40%, #000 55%, transparent 100%);
}
.hero-inner { position: relative; z-index: 1; }
.venue-tag {
  background: #fff; color: var(--accent); border: 1px solid var(--line);
  font-weight: 600; letter-spacing: 0.03em; margin-bottom: 1.2rem;
}
.publication-title {
  max-width: 840px; margin: 0 auto 1.3rem; line-height: 1.18;
  letter-spacing: -0.02em;
}
.publication-authors { font-size: 1.1rem; margin-bottom: 0.4rem; }
.author-block { display: inline-block; margin: 0 0.15rem; }
.author-block a { color: var(--accent); font-weight: 600; border-bottom: 1px solid transparent; transition: border-color .12s; }
.author-block a:hover { border-bottom-color: var(--accent); }
.author-block sup { color: var(--accent); }
.publication-affiliation { color: var(--muted); font-size: 0.9rem; margin-bottom: 1.6rem; }
.publication-affiliation sup { color: var(--accent); font-weight: 700; }

.publication-links { display: flex; flex-wrap: wrap; gap: 0.6rem; justify-content: center; }
.link-btn { background: var(--ink); color: #fff; font-weight: 600; transition: transform .12s, background .12s; }
.link-btn:hover { background: var(--accent); color: #fff; transform: translateY(-2px); }

/* ---------- key highlights ---------- */
.highlights {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem;
  margin-top: 2.6rem; text-align: left;
}
.hl-card {
  display: flex; flex-direction: column;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.35rem 1.2rem; position: relative; overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform .15s, box-shadow .15s;
}
.hl-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.hl-card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-soft));
}
.hl-head {
  display: flex; align-items: center; gap: 0.7rem; margin-bottom: 0.7rem;
}
.hl-icon {
  flex: 0 0 auto;
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 12px;
  background: rgba(181,18,27,0.09); color: var(--accent); font-size: 1.25rem;
}
.hl-title {
  flex: 1; margin: 0;
  font-weight: 800; font-size: 1.05rem; letter-spacing: -0.01em; line-height: 1.2;
}
.hl-figure { color: var(--accent); font-size: 1.5em; font-weight: 800; }
.hl-sub {
  color: var(--muted); font-size: 0.84rem; line-height: 1.5;
  flex: 1 1 auto; margin-bottom: 0.85rem;
}
.hl-chips { display: flex; flex-wrap: wrap; gap: 0.35rem; margin-top: auto; }
.hl-chips span {
  font-size: 0.68rem; font-weight: 700; color: var(--accent);
  background: rgba(181,18,27,0.08); border: 1px solid rgba(181,18,27,0.18);
  border-radius: 999px; padding: 0.14rem 0.6rem;
}
@media (max-width: 900px) { .highlights { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .highlights { grid-template-columns: 1fr; } }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- abstract ---------- */
.abstract-body { font-size: 1.05rem; line-height: 1.75; max-width: 820px; margin: 0 auto; }

/* ---------- charts ---------- */
.chart-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.2rem 1.2rem 0.6rem; box-shadow: var(--shadow);
}
.compare-toggle { color: var(--muted); font-size: 0.9rem; margin-left: 0.5rem; }

/* scaling section (sampling + repair) */
.chart-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 0.5rem; margin-bottom: 0.6rem; flex-wrap: wrap;
}
.chart-title { font-weight: 800; font-size: 1.02rem; color: var(--ink); }
.chart-title i { color: var(--accent); margin-right: 0.35rem; }
.chart-note { font-size: 0.76rem; color: var(--muted); }

/* ---------- chips (shared) ---------- */
.filter-chips { display: inline-flex; flex-wrap: wrap; gap: 0.4rem; }
.chip {
  cursor: pointer; user-select: none;
  padding: 0.2rem 0.7rem; border-radius: 999px;
  font-size: 0.78rem; font-weight: 600;
  background: #fff; border: 1px solid var(--line); color: var(--muted);
  transition: all .12s;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.is-active { background: var(--ink); color: #fff; border-color: var(--ink); }
.chip.is-static { cursor: default; }
.chip.is-static:hover { border-color: var(--line); color: var(--muted); }
.diff-Easy   { color: #1a8a4b; border-color: #bfe6cd; }
.diff-Medium { color: #b3760a; border-color: #f0dcae; }
.diff-Hard   { color: #b5121b; border-color: #f0c0c3; }
.chip.diff-Easy.is-active   { background: #1a8a4b; color:#fff; border-color:#1a8a4b; }
.chip.diff-Medium.is-active { background: #b3760a; color:#fff; border-color:#b3760a; }
.chip.diff-Hard.is-active   { background: #b5121b; color:#fff; border-color:#b5121b; }

/* ---------- explorer ---------- */
.explorer-controls { margin-bottom: 1.4rem; text-align: center; }
.explorer-controls .filter-chips { justify-content: center; }
.filter-groups { display: flex; flex-direction: column; gap: 0.5rem; align-items: flex-end; }
.explorer-body { align-items: stretch; }
.problem-list { max-height: 560px; overflow-y: auto; padding-right: 4px; }
.problem-item {
  background: #fff; border: 1px solid var(--line); border-left: 3px solid transparent;
  border-radius: var(--radius-sm); padding: 0.7rem 0.9rem; margin-bottom: 0.55rem; cursor: pointer;
  transition: border-color .12s, transform .12s, box-shadow .12s;
}
.problem-item:hover { transform: translateX(2px); box-shadow: var(--shadow); }
.problem-item.is-selected { border-left-color: var(--accent); background: #fff; box-shadow: 0 4px 16px rgba(181,18,27,0.08); }
.pi-head { display: flex; justify-content: space-between; align-items: baseline; gap: 0.5rem; }
.pi-title { font-weight: 700; font-size: 0.95rem; }
.pi-meta { margin-top: 0.4rem; display: flex; flex-wrap: wrap; gap: 0.3rem; align-items: center; }
.pi-tag { font-size: 0.68rem; color: var(--muted); background: var(--tint); border-radius: 5px; padding: 0.05rem 0.4rem; }
.pi-id { font-size: 0.68rem; font-weight: 700; color: var(--muted); font-family: "SFMono-Regular", Menlo, monospace; }

/* link to the problem's official page */
.prob-link {
  font-size: 0.78rem; font-weight: 700; color: var(--accent);
  display: inline-flex; align-items: center; gap: 0.3rem;
  padding: 0.08rem 0.55rem; border-radius: 999px;
  border: 1px solid rgba(181,18,27,0.22); background: rgba(181,18,27,0.06);
  transition: background .12s, color .12s;
}
.prob-link:hover { background: var(--accent); color: #fff; }
.prob-link i { font-size: 0.7em; }

.src-badge { font-size: 0.68rem; font-weight: 700; padding: 0.08rem 0.45rem; border-radius: 5px; color: #fff; }
.src-LeetCode { background: #e08a2e; }
.src-Codeforces { background: #3f5ec9; }

/* level badge: LeetCode difficulty (colored) or Codeforces numeric rating */
.lvl-badge {
  font-size: 0.68rem; font-weight: 700; white-space: nowrap;
  padding: 0.08rem 0.5rem; border-radius: 999px;
  border: 1px solid var(--line); color: var(--muted); background: #fff;
}
.lvl-badge.diff-Easy   { color: #1a8a4b; border-color: #bfe6cd; background: #f2faf5; }
.lvl-badge.diff-Medium { color: #b3760a; border-color: #f0dcae; background: #fdf8ee; }
.lvl-badge.diff-Hard   { color: #b5121b; border-color: #f0c0c3; background: #fdf2f3; }
.lvl-badge.rating-badge { color: #3f5ec9; border-color: #c3ccef; background: #f2f5fd; }

.problem-detail { min-height: 560px; }
.detail-head { border-bottom: 1px solid var(--line); padding-bottom: 0.8rem; margin-bottom: 0.4rem; }
.detail-title { font-size: 1.3rem; font-weight: 800; margin-bottom: 0.35rem; }
.detail-sub { display: flex; gap: 0.4rem; align-items: center; flex-wrap: wrap; }
.detail-meta { color: var(--muted); font-size: 0.8rem; }
.detail-tabs { margin-bottom: 0.5rem; }
.detail-tabs li.is-active a { color: var(--accent); border-bottom-color: var(--accent); }
.detail-panel { max-height: 420px; overflow: auto; }
.detail-panel pre { border-radius: 8px; border: 1px solid var(--line); }
.detail-panel.content { padding: 0.4rem 0.2rem; }
.detail-panel.content > p:first-child { margin-top: 0; }
.detail-panel.content p { margin-bottom: 0.55rem; }
.detail-panel.content pre {
  background: var(--tint); font-size: 0.82rem; padding: 0.7rem 0.9rem;
  margin: 0.4rem 0 0.9rem; line-height: 1.45;
}
.detail-panel.content ul { margin: 0.2rem 0 0.9rem 1rem; }
.detail-panel.content strong { color: var(--ink); }
.detail-panel.content h2,
.detail-panel.content h3 {
  font-size: 0.95rem; font-weight: 800; color: var(--ink);
  margin: 1.05rem 0 0.4rem;
}
.detail-panel.content blockquote {
  border-left: 3px solid var(--accent); background: var(--tint);
  padding: 0.55rem 0.85rem; margin: 0.35rem 0 0.9rem;
  border-radius: 0 8px 8px 0; color: var(--ink); font-size: 0.85rem;
}
.detail-panel.content blockquote strong { color: var(--accent); }

/* ---------- leaderboard ---------- */
.lb-toolbar { margin-bottom: 0.9rem; }

.lb-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 0.4rem 0.6rem; overflow-x: auto;
}
#lbTable {
  font-size: 0.92rem; border-collapse: separate; border-spacing: 0; margin-bottom: 0;
  table-layout: fixed; width: 100%; min-width: 1020px;
}
/* fixed columns: rank + model sized; the six metric columns share the rest equally */
#lbTable .col-rank { width: 48px; }
#lbTable .col-model { width: 230px; }
#lbTable .col-metric { width: auto; }
#lbTable thead th { color: var(--ink); vertical-align: middle; border: none; padding-bottom: 0.5rem; }
#lbTable thead tr:last-child th { border-bottom: 2px solid var(--line); padding-bottom: 0.6rem; }
#lbTable th.sortable { cursor: pointer; user-select: none; white-space: nowrap; }
#lbTable th.sortable:hover { color: var(--accent); }
.rank-th { width: 46px; text-align: center; color: var(--muted) !important; }
.sort-ic { color: #c4c4cc; font-size: 0.72em; margin-left: 2px; }
.sort-ic.is-active-sort { color: var(--accent); }
.group-th { color: var(--muted) !important; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; }
.sub-th { font-weight: 600; color: #777 !important; font-size: 0.73rem; white-space: nowrap; }

/* rows */
.lb-row td { vertical-align: middle; border-bottom: 1px solid #f0f0f4; padding: 0.4rem 0.5rem; }
.lb-row:last-child td { border-bottom: none; }
.lb-row:hover td { background: var(--tint); }
.lb-row.is-champion td { background: linear-gradient(90deg, rgba(224,138,46,0.13), rgba(224,138,46,0.02) 60%, transparent); }
.lb-row.is-champion:hover td { background: linear-gradient(90deg, rgba(224,138,46,0.18), rgba(224,138,46,0.04) 60%, var(--tint)); }

/* rank */
.rank-cell { text-align: center; }
.medal { font-size: 1.25rem; line-height: 1; }
.rank-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--tint); color: var(--muted); font-weight: 700; font-size: 0.8rem;
}

/* model identity */
.model-cell { white-space: nowrap; }
.prov-avatar {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 9px; color: #fff;
  font-weight: 800; font-size: 0.95rem; margin-right: 0.65rem; vertical-align: middle;
  box-shadow: 0 2px 6px rgba(0,0,0,0.14);
}
.model-info { display: inline-flex; flex-direction: column; vertical-align: middle; line-height: 1.15; }
.model-name { font-weight: 700; }
.model-prov { font-size: 0.7rem; color: var(--muted); }

/* metric cells: clean numbers, centered under their headers, best score chipped */
#lbTable td.num { text-align: center; }
.num .v { font-variant-numeric: tabular-nums; font-size: 0.88rem; }
.num.is-best .v {
  background: rgba(181,18,27,0.09); color: var(--accent); font-weight: 800;
  padding: 0.12rem 0.5rem; border-radius: 7px;
}

/* task-group separators + header alignment — headers and numbers both centered */
#lbTable thead th.group-th { text-align: center; }
#lbTable thead th.sub-th { text-align: center; }
.col-sep { border-left: 1px solid var(--line) !important; }

/* task-definition legend under the table */
.lb-defs {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 0.4rem 1.2rem; margin-top: 1rem; font-size: 0.78rem; color: var(--muted);
}
.lb-defs b { color: var(--ink); }
.best-key {
  background: rgba(181,18,27,0.09); color: var(--accent);
  padding: 0 0.3rem; border-radius: 5px;
}

/* ---------- dataset ---------- */
.artifact-list { list-style: none; margin-left: 0; }
.artifact-list li { margin-bottom: 0.4rem; color: var(--muted); }
.art-badge {
  display: inline-block; min-width: 96px; text-align: center;
  font-family: "SFMono-Regular", Menlo, monospace; font-size: 0.72rem;
  background: var(--ink); color: #fff; border-radius: 5px; padding: 0.1rem 0.45rem; margin-right: 0.5rem;
}

.pipeline { align-items: stretch; }
.pipeline-box { height: 100%; border-top: 3px solid var(--accent); }
.pipeline-icon { display: block; font-size: 1.6rem; color: var(--accent); margin-bottom: 0.5rem; }
.pipeline-arrow { display: flex; align-items: center; justify-content: center; color: #c4c4cc; flex: 0 0 auto; }
@media (max-width: 768px) { .pipeline-arrow { transform: rotate(90deg); padding: 0.3rem 0; } }
.quality-tags .tag { background: #fff; border: 1px solid var(--line); color: var(--ink); font-weight: 500; }
.quality-tags .tag i { color: #1a8a4b; }

/* ---------- citation ---------- */
.bibtex-wrap { position: relative; max-width: 820px; margin: 0 auto; }
.bibtex-wrap pre { border-radius: var(--radius); border: 1px solid var(--line); background: #fff; box-shadow: var(--shadow); }
.copy-btn { position: absolute; top: 0.7rem; right: 0.7rem; z-index: 2; }

/* ---------- footer ---------- */
.footer { background: #fafafb; border-top: 1px solid var(--line); }

pre { overflow-x: auto; }