:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #f59e0b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --bg-dark: #0f172a;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --code-bg: #f1f5f9;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.05);
  --radius: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--bg);
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Hero ── */
.hero {
  text-align: center;
  padding: 80px 0 48px;
  background: linear-gradient(135deg, #eff6ff 0%, #f0f9ff 50%, #fefce8 100%);
  border-bottom: 1px solid var(--border);
}

.hero-logo {
  width: 120px;
  height: 120px;
  margin-bottom: 24px;
  border-radius: 24px;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--bg-dark);
  max-width: 800px;
  margin: 0 auto 16px;
}

.hero .subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  font-weight: 400;
}

.authors {
  font-size: 1.05rem;
  margin-bottom: 6px;
  color: var(--text);
}

.authors a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

.authors a:hover { text-decoration: underline; }

.affiliations {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.venue-tag {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 28px;
  letter-spacing: 0.5px;
}

.badges {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
}

.badge:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.badge.arxiv { border-color: #b91c1c; color: #b91c1c; }
.badge.github { border-color: #1f2937; color: #1f2937; }
.badge.hf { border-color: #f59e0b; color: #92400e; }
.badge.dataset { border-color: #2563eb; color: #2563eb; }

.badge svg { width: 18px; height: 18px; flex-shrink: 0; }

/* ── Sections ── */
section {
  padding: 56px 0;
  border-bottom: 1px solid var(--border);
}

section:last-child { border-bottom: none; }

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

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--bg-dark);
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-title .icon {
  font-size: 1.4rem;
}

h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 32px 0 12px;
  color: var(--bg-dark);
}

p { margin-bottom: 16px; }

/* ── Figure Placeholder ── */
.figure-container {
  margin: 32px 0;
  text-align: center;
}

.figure-placeholder {
  border: 3px dashed var(--border);
  border-radius: var(--radius);
  padding: 60px 32px;
  background: var(--bg-alt);
  color: var(--text-muted);
  font-size: 0.95rem;
  position: relative;
  transition: border-color 0.2s;
}

.figure-placeholder:hover {
  border-color: var(--primary);
}

.figure-placeholder .placeholder-label {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
  position: absolute;
  top: 12px;
  left: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.figure-placeholder .placeholder-icon {
  font-size: 2.5rem;
  display: block;
  margin-bottom: 12px;
  opacity: 0.5;
}

.figure-placeholder .placeholder-text {
  font-weight: 600;
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 4px;
}

.figure-placeholder .placeholder-hint {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.figure-img {
  max-width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.figure-caption {
  margin-top: 12px;
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
}

.figure-caption strong {
  color: var(--text);
  font-style: normal;
}

/* ── Example Placeholder ── */
.example-container {
  margin: 24px 0;
}

.example-placeholder {
  border: 2px dashed #d97706;
  border-radius: var(--radius);
  padding: 40px 24px;
  background: #fffbeb;
  text-align: center;
  position: relative;
}

.example-placeholder .placeholder-label {
  display: inline-block;
  background: #d97706;
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
  position: absolute;
  top: 12px;
  left: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.example-placeholder .placeholder-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 8px;
  opacity: 0.6;
}

.example-placeholder .placeholder-text {
  font-weight: 600;
  color: #92400e;
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.example-placeholder .placeholder-hint {
  font-size: 0.85rem;
  color: #b45309;
}

/* ── Contribution Cards ── */
.contrib-grid {
  display: grid;
  gap: 16px;
  margin-top: 20px;
}

.contrib-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}

.contrib-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.contrib-card .card-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.contrib-card h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--bg-dark);
}

.contrib-card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ── Tables ── */
.table-wrapper {
  overflow-x: auto;
  margin: 20px 0;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

thead {
  background: var(--bg-dark);
  color: #fff;
}

th {
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

tbody tr:last-child td { border-bottom: none; }

tbody tr:hover { background: #f8fafc; }

.highlight-row {
  background: #eff6ff !important;
  font-weight: 600;
}

.highlight-row:hover {
  background: #dbeafe !important;
}

.best-val {
  font-weight: 700;
  color: var(--primary-dark);
}

/* ── Methodology Steps ── */
.method-steps {
  counter-reset: step;
}

.method-step {
  position: relative;
  padding: 24px 24px 24px 72px;
  margin-bottom: 20px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.method-step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 20px;
  top: 24px;
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.method-step h4 {
  font-size: 1.05rem;
  margin-bottom: 8px;
  color: var(--bg-dark);
}

.method-step p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ── Model Zoo ── */
.model-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 6px;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.model-badge.pointwise { background: #dbeafe; color: #1e40af; }
.model-badge.pairwise { background: #fef3c7; color: #92400e; }

/* ── Citation ── */
.citation-block {
  background: var(--bg-dark);
  color: #e2e8f0;
  border-radius: var(--radius);
  padding: 24px;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85rem;
  line-height: 1.6;
  overflow-x: auto;
  position: relative;
}

.citation-block .copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  background: #334155;
  color: #e2e8f0;
  border: none;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 0.8rem;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.15s;
}

.citation-block .copy-btn:hover { background: #475569; }

/* ── Two-column layout ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin: 24px 0;
}

/* ── Footer ── */
footer {
  text-align: center;
  padding: 40px 0;
  color: var(--text-muted);
  font-size: 0.85rem;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
}

footer a { color: var(--primary); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .hero { padding: 48px 0 32px; }
  .hero h1 { font-size: 1.5rem; }
  .badges { gap: 8px; }
  .badge { padding: 8px 14px; font-size: 0.8rem; }
  .section-title { font-size: 1.3rem; }
  .two-col { grid-template-columns: 1fr; }
  .method-step { padding-left: 60px; }
  .table-wrapper { font-size: 0.8rem; }
}