/* ===== CSS Variables ===== */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: #1a2236;
  --bg-card-hover: #1f2a42;
  --border: #2a3450;
  --text-primary: #f0f2f5;
  --text-secondary: #9ba3b5;
  --text-muted: #6b7280;
  --accent: #6366f1;
  --accent-light: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.15);
  --green: #10b981;
  --green-bg: rgba(16, 185, 129, 0.1);
  --blue: #3b82f6;
  --blue-bg: rgba(59, 130, 246, 0.1);
  --orange: #f59e0b;
  --red: #ef4444;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.4);
  --transition: 0.2s ease;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 14, 26, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.15rem;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--accent), #a855f7);
  border-radius: 8px;
  font-weight: 800;
  font-size: 0.85rem;
  color: #fff;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.nav-links a:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.nav-btn {
  background: var(--accent) !important;
  color: #fff !important;
  padding: 0.5rem 1.25rem !important;
  border-radius: 8px !important;
  font-weight: 600 !important;
}

.nav-btn:hover {
  background: var(--accent-light) !important;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 4.5rem 0 0.5rem;
  text-align: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(99, 102, 241, 0.12) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 20% 50%, rgba(168, 85, 247, 0.06) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 50%, rgba(59, 130, 246, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
}

.hero-badge {
  display: inline-block;
  padding: 0.35rem 1rem;
  background: var(--accent-glow);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-light);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  background: linear-gradient(135deg, #fff 0%, #c7d2fe 50%, var(--accent-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 0;
  line-height: 1.5;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  max-width: 800px;
  margin: 0 auto 3rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-light);
  font-family: var(--font-mono);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.hero-description {
  max-width: 750px;
  margin: 0 auto;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}

/* ===== Sections ===== */
.section {
  padding: 1rem 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  text-align: center;
}

.section-description {
  text-align: center;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 2.5rem;
  font-size: 1.05rem;
  line-height: 1.6;
}

/* ===== Findings ===== */
.findings {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.findings-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-top: 2rem;
}

.finding-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: border-color var(--transition), transform var(--transition);
}

.finding-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.finding-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--accent-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.finding-icon svg {
  width: 22px;
  height: 22px;
  color: var(--accent-light);
}

.finding-card h3 {
  font-size: 1.05rem;
  font-weight: 650;
  margin-bottom: 0.5rem;
}

.finding-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.55;
}

/* ===== Leaderboard ===== */
.leaderboard-controls {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.filter-group label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.filter-group select {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.85rem;
  font-size: 0.85rem;
  font-family: var(--font-sans);
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition);
}

.filter-group select:focus {
  border-color: var(--accent);
}

.table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
}

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

.leaderboard-table thead {
  background: rgba(255, 255, 255, 0.03);
}

.leaderboard-table th {
  padding: 0.85rem 1rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
  user-select: none;
}

.leaderboard-table th.sortable {
  cursor: pointer;
}

.leaderboard-table th.sortable:hover {
  color: var(--text-primary);
}

.leaderboard-table th.active {
  color: var(--accent-light);
}

.leaderboard-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid rgba(42, 52, 80, 0.5);
  white-space: nowrap;
}

.leaderboard-table tbody tr {
  transition: background var(--transition);
}

.leaderboard-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

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

.rank-col { width: 50px; text-align: center; }
.leaderboard-table th.score-col,
.leaderboard-table td.score-col { text-align: center; }

.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.8rem;
}

.rank-1 { background: linear-gradient(135deg, #fbbf24, #f59e0b); color: #000; }
.rank-2 { background: linear-gradient(135deg, #94a3b8, #64748b); color: #000; }
.rank-3 { background: linear-gradient(135deg, #d97706, #b45309); color: #fff; }
.rank-default { background: var(--bg-secondary); color: var(--text-secondary); }

.model-name {
  font-weight: 600;
  color: var(--text-primary);
}

.provider-badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
}

.provider-openai { background: rgba(16, 163, 127, 0.15); color: #34d399; }
.provider-anthropic { background: rgba(217, 119, 6, 0.15); color: #fbbf24; }
.provider-google { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.provider-meta { background: rgba(99, 102, 241, 0.15); color: #a5b4fc; }
.provider-microsoft { background: rgba(14, 165, 233, 0.15); color: #38bdf8; }
.provider-deepseek { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.provider-ibm { background: rgba(239, 68, 68, 0.15); color: #f87171; }
.provider-other { background: rgba(107, 114, 128, 0.15); color: #9ca3af; }

.score-value {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.9rem;
}

.score-bar-cell {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.score-bar-bg {
  width: 60px;
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  overflow: hidden;
}

.score-bar-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.5s ease;
}

.row-top { background: rgba(16, 185, 129, 0.04); }
.row-opensource { background: rgba(59, 130, 246, 0.04); }

/* ===== Charts ===== */
.chart-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.chart-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.chart-card.wide {
  width: 100%;
}

.chart-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.chart-container {
  position: relative;
  width: 100%;
  height: 350px;
}

.chart-container.tall {
  height: 450px;
}

/* ===== Comparison ===== */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.comparison-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}

.comparison-card h3 {
  font-size: 1.1rem;
  font-weight: 650;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.comparison-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.comp-stat {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.comp-value {
  font-size: 1.75rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-primary);
}

.comp-value.highlight {
  color: var(--accent-light);
}

.comp-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ===== Sample Questions ===== */
.questions-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: border-color var(--transition);
}

.question-card:hover {
  border-color: var(--accent);
}

.question-number {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-light);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.question-text {
  font-size: 0.95rem;
  font-weight: 500;
  margin-bottom: 1rem;
  line-height: 1.5;
}

.question-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.option {
  display: flex;
  gap: 0.5rem;
  padding: 0.6rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  transition: var(--transition);
  line-height: 1.45;
}

.option .option-letter {
  font-weight: 700;
  color: var(--text-muted);
  flex-shrink: 0;
}

.option.correct {
  background: var(--green-bg);
  border-color: rgba(16, 185, 129, 0.3);
  color: var(--green);
}

.option.correct .option-letter {
  color: var(--green);
}

.load-more-container {
  text-align: center;
  margin-top: 2rem;
}

.btn-load-more {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.7rem 2rem;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}

.btn-load-more:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

/* ===== Dataset ===== */
.dataset-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 2rem;
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

.dataset-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  text-align: center;
  transition: border-color var(--transition), transform var(--transition);
}

.dataset-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.dataset-number {
  font-size: 2.25rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent-light);
  margin-bottom: 0.25rem;
}

.dataset-name {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.dataset-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.data-link {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.45rem 1.1rem;
  background: var(--accent-glow);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-sm);
  color: var(--accent-light);
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition);
}

.data-link:hover {
  background: rgba(99, 102, 241, 0.25);
  border-color: var(--accent-light);
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 3rem 0;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.1rem;
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--text-primary);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .findings-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .dataset-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
  }

  .chart-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(10, 14, 26, 0.98);
    backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 1rem;
    border-bottom: 1px solid var(--border);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: 8rem 0 3rem;
  }

  .hero h1 {
    font-size: 2.25rem;
  }

  .findings-grid {
    grid-template-columns: 1fr;
  }

  .comparison-grid,
  .questions-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .section {
    padding: 3rem 0;
  }

  .section-title {
    font-size: 1.6rem;
  }
}

@media (max-width: 480px) {
  .hero-stats {
    grid-template-columns: 1fr;
  }

  .comparison-stats {
    grid-template-columns: 1fr;
  }

  .leaderboard-controls {
    flex-direction: column;
  }
}