/* ===== CSS Variables ===== */
:root {
  --lb-primary: #4f46e5;
  --lb-primary-light: #818cf8;
  --lb-primary-dark: #3730a3;
  --lb-accent: #06b6d4;
  --lb-accent-light: #67e8f9;
  --lb-bg: #f8fafc;
  --lb-surface: #ffffff;
  --lb-text: #0f172a;
  --lb-text-secondary: #64748b;
  --lb-border: #e2e8f0;
  --lb-hover: #f1f5f9;
  --lb-gold: #f59e0b;
  --lb-silver: #94a3b8;
  --lb-bronze: #d97706;
  --lb-best: #059669;
  --lb-gradient-start: #4f46e5;
  --lb-gradient-end: #06b6d4;
  --lb-shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.05);
  --lb-shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --lb-shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
  --lb-shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
  --lb-radius: 12px;
  --lb-radius-sm: 8px;
}

/* ===== Page Layout ===== */
.leaderboard-page {
  background: var(--lb-bg);
  min-height: 100vh;
}

/* ===== Hero Section ===== */
.leaderboard-hero {
  background: linear-gradient(135deg, var(--lb-gradient-start) 0%, var(--lb-gradient-end) 100%);
  padding: 3rem 1.5rem 2.5rem;
  position: relative;
  overflow: hidden;
}

.leaderboard-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 30px 30px;
  animation: heroPattern 20s linear infinite;
}

@keyframes heroPattern {
  0% { transform: translate(0, 0); }
  100% { transform: translate(30px, 30px); }
}

.leaderboard-hero .hero-content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.leaderboard-hero h1 {
  font-family: 'Google Sans', 'Noto Sans', sans-serif;
  font-size: 2.5rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.leaderboard-hero .hero-icon {
  font-size: 2.8rem;
  margin-bottom: 0.5rem;
  display: block;
}

.leaderboard-hero p {
  font-family: 'Noto Sans', sans-serif;
  font-size: 1.1rem;
  color: rgba(255,255,255,0.85);
  max-width: 650px;
  margin: 0 auto;
  line-height: 1.6;
}

.hero-back-link {
  position: absolute;
  top: 1.5rem;
  left: 1.5rem;
  z-index: 2;
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  font-size: 0.95rem;
  font-family: 'Noto Sans', sans-serif;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: color 0.2s ease;
}

.hero-back-link:hover {
  color: #ffffff;
}

/* ===== Section Background ===== */
.leaderboard-section {
  background: var(--lb-bg);
}

/* ===== Main Content ===== */
.leaderboard-content {
  max-width: 1200px;
  margin: -1.5rem auto 2rem;
  padding: 0 1.5rem;
  position: relative;
  z-index: 2;
}

/* ===== Tab Toggle ===== */
.tab-container {
  display: flex;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.tab-toggle {
  display: inline-flex;
  background: var(--lb-surface);
  border-radius: 50px;
  padding: 5px;
  box-shadow: var(--lb-shadow-lg);
  gap: 4px;
}

.tab-btn {
  font-family: 'Google Sans', 'Noto Sans', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.6rem 1.8rem;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  background: transparent;
  color: var(--lb-text-secondary);
  position: relative;
  white-space: nowrap;
}

.tab-btn:hover:not(.active) {
  color: var(--lb-text);
  background: var(--lb-hover);
}

.tab-btn.active {
  background: linear-gradient(135deg, var(--lb-gradient-start), var(--lb-gradient-end));
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.35);
}

.tab-btn .tab-icon {
  margin-right: 0.4rem;
}

/* ===== Sort Info ===== */
.sort-info {
  text-align: center;
  font-family: 'Noto Sans', sans-serif;
  font-size: 0.85rem;
  color: var(--lb-text-secondary);
  margin-bottom: 1rem;
}

.sort-info span {
  background: var(--lb-surface);
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  box-shadow: var(--lb-shadow-sm);
}

/* ===== Table Card ===== */
.table-card {
  background: var(--lb-surface);
  border-radius: var(--lb-radius);
  box-shadow: var(--lb-shadow-xl);
  overflow: hidden;
  animation: fadeInUp 0.5s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Table ===== */
.leaderboard-table-wrapper {
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--lb-border) transparent;
}

.leaderboard-table-wrapper::-webkit-scrollbar {
  height: 6px;
}

.leaderboard-table-wrapper::-webkit-scrollbar-track {
  background: transparent;
}

.leaderboard-table-wrapper::-webkit-scrollbar-thumb {
  background: var(--lb-border);
  border-radius: 3px;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'Noto Sans', sans-serif;
  font-size: 0.92rem;
  min-width: 850px;
}

/* ===== Table Header ===== */
.leaderboard-table thead {
  position: sticky;
  top: 0;
  z-index: 10;
}

.leaderboard-table thead tr.header-group th {
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  color: rgba(255,255,255,0.95);
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.65rem 0.8rem;
  border-bottom: none;
  text-align: center;
  white-space: nowrap;
}

.leaderboard-table thead tr.header-group th.level-l1 {
  border-bottom: 3px solid #60a5fa;
}
.leaderboard-table thead tr.header-group th.level-l2 {
  border-bottom: 3px solid #a78bfa;
}
.leaderboard-table thead tr.header-group th.level-l3 {
  border-bottom: 3px solid #34d399;
}
.leaderboard-table thead tr.header-group th.level-l4 {
  border-bottom: 3px solid #fbbf24;
}

.leaderboard-table thead tr.header-metrics th {
  background: #1e293b;
  color: rgba(255,255,255,0.85);
  font-weight: 500;
  font-size: 0.8rem;
  padding: 0.5rem 0.8rem;
  border-bottom: 2px solid var(--lb-border);
  text-align: center;
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
  transition: background 0.2s ease;
  position: relative;
}

.leaderboard-table thead tr.header-metrics th:hover {
  background: #334155;
}

.leaderboard-table thead tr.header-metrics th .sort-arrow {
  margin-left: 0.3rem;
  font-size: 0.7rem;
  opacity: 0.4;
  transition: opacity 0.2s ease;
}

.leaderboard-table thead tr.header-metrics th.sort-active .sort-arrow {
  opacity: 1;
  color: var(--lb-accent-light);
}

.leaderboard-table thead tr.header-metrics th.col-rank,
.leaderboard-table thead tr.header-metrics th.col-model {
  text-align: left;
  cursor: default;
}

.leaderboard-table thead tr.header-metrics th.col-rank {
  padding-left: 1.2rem;
  width: 60px;
}

/* ===== Table Body ===== */
.leaderboard-table tbody tr {
  transition: all 0.2s ease;
  border-bottom: 1px solid var(--lb-border);
}

.leaderboard-table tbody tr:last-child {
  border-bottom: none;
}

.leaderboard-table tbody tr:hover {
  background: var(--lb-hover);
  transform: scale(1.002);
}

.leaderboard-table tbody tr.rank-1 {
  background: linear-gradient(90deg, rgba(245,158,11,0.08) 0%, transparent 50%);
}

.leaderboard-table tbody tr.rank-2 {
  background: linear-gradient(90deg, rgba(148,163,184,0.08) 0%, transparent 50%);
}

.leaderboard-table tbody tr.rank-3 {
  background: linear-gradient(90deg, rgba(217,119,6,0.08) 0%, transparent 50%);
}

.leaderboard-table tbody td {
  padding: 0.75rem 0.8rem;
  text-align: center;
  font-variant-numeric: tabular-nums;
  vertical-align: middle;
}

.leaderboard-table tbody td.col-rank {
  text-align: left;
  padding-left: 1.2rem;
  font-weight: 700;
  font-size: 0.95rem;
}

.leaderboard-table tbody td.col-model {
  text-align: left;
  white-space: nowrap;
}

/* ===== Model Name ===== */
.model-info {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}

.model-family {
  font-size: 0.75rem;
  color: var(--lb-text-secondary);
  font-weight: 500;
}

.model-version {
  font-weight: 600;
  color: var(--lb-text);
  font-size: 0.92rem;
}

/* ===== Rank Badges ===== */
.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  font-size: 0.82rem;
  font-weight: 700;
}

.rank-badge.gold {
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
  color: #78350f;
  box-shadow: 0 2px 6px rgba(245,158,11,0.4);
}

.rank-badge.silver {
  background: linear-gradient(135deg, #cbd5e1, #94a3b8);
  color: #1e293b;
  box-shadow: 0 2px 6px rgba(148,163,184,0.4);
}

.rank-badge.bronze {
  background: linear-gradient(135deg, #fdba74, #f97316);
  color: #7c2d12;
  box-shadow: 0 2px 6px rgba(249,115,22,0.3);
}

.rank-badge.normal {
  background: var(--lb-hover);
  color: var(--lb-text-secondary);
}

/* ===== Score Cells ===== */
.score-cell {
  position: relative;
}

.score-value {
  position: relative;
  z-index: 1;
  font-weight: 500;
}

.score-cell.best-in-col .score-value {
  font-weight: 700;
  color: var(--lb-best);
}

.score-cell .score-bar {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  opacity: 0.08;
  transition: opacity 0.2s ease;
  pointer-events: none;
}

.leaderboard-table tbody tr:hover .score-bar {
  opacity: 0.14;
}

.score-bar.bar-l1 { background: #3b82f6; }
.score-bar.bar-l2 { background: #8b5cf6; }
.score-bar.bar-l3 { background: #10b981; }
.score-bar.bar-l4 { background: #f59e0b; }

/* ===== Legend ===== */
.legend-bar {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  padding: 1rem 1.5rem;
  background: #f8fafc;
  border-top: 1px solid var(--lb-border);
  font-family: 'Noto Sans', sans-serif;
  font-size: 0.82rem;
  color: var(--lb-text-secondary);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.legend-dot.l1 { background: #3b82f6; }
.legend-dot.l2 { background: #8b5cf6; }
.legend-dot.l3 { background: #10b981; }
.legend-dot.l4 { background: #f59e0b; }
.legend-dot.best { background: var(--lb-best); }

/* ===== Metric Description ===== */
.metric-description {
  max-width: 1200px;
  margin: 1.5rem auto 0;
  padding: 0 1.5rem;
}

.metric-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.metric-card {
  background: var(--lb-surface);
  border-radius: var(--lb-radius-sm);
  padding: 1.2rem;
  box-shadow: var(--lb-shadow-md);
  border-left: 4px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.metric-card.card-l1 { border-left-color: #3b82f6; }
.metric-card.card-l2 { border-left-color: #8b5cf6; }
.metric-card.card-l3 { border-left-color: #10b981; }
.metric-card.card-l4 { border-left-color: #f59e0b; }

.metric-card h4 {
  font-family: 'Google Sans', 'Noto Sans', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--lb-text);
  margin-bottom: 0.3rem;
}

.metric-card .level-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.15rem 0.5rem;
  border-radius: 20px;
  margin-bottom: 0.4rem;
}

.level-tag.tag-l1 { background: rgba(59,130,246,0.12); color: #2563eb; }
.level-tag.tag-l2 { background: rgba(139,92,246,0.12); color: #7c3aed; }
.level-tag.tag-l3 { background: rgba(16,185,129,0.12); color: #059669; }
.level-tag.tag-l4 { background: rgba(245,158,11,0.12); color: #d97706; }

.metric-card p {
  font-family: 'Noto Sans', sans-serif;
  font-size: 0.82rem;
  color: var(--lb-text-secondary);
  line-height: 1.5;
  margin: 0;
}

/* ===== Row Animation ===== */
.leaderboard-table tbody tr {
  animation: rowSlideIn 0.4s ease-out both;
}

@keyframes rowSlideIn {
  from {
    opacity: 0;
    transform: translateX(-10px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Stagger delays are applied via JS */

/* ===== Footer ===== */
.leaderboard-footer {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  text-align: center;
}

.leaderboard-footer p {
  font-family: 'Noto Sans', sans-serif;
  font-size: 0.85rem;
  color: var(--lb-text-secondary);
  line-height: 1.6;
}

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

.leaderboard-footer a:hover {
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .leaderboard-hero {
    padding: 2rem 1rem 2rem;
  }

  .leaderboard-hero h1 {
    font-size: 1.6rem;
  }

  .leaderboard-hero p {
    font-size: 0.95rem;
  }

  .leaderboard-content {
    padding: 0 0.75rem;
  }

  .tab-btn {
    font-size: 0.85rem;
    padding: 0.5rem 1.2rem;
  }

  .metric-cards {
    grid-template-columns: 1fr;
  }

  .hero-back-link {
    top: 0.8rem;
    left: 0.8rem;
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  .leaderboard-hero h1 {
    font-size: 1.3rem;
  }

  .tab-btn {
    font-size: 0.8rem;
    padding: 0.45rem 0.9rem;
  }

  .legend-bar {
    gap: 0.8rem;
    font-size: 0.75rem;
  }
}