:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2233;
  --bg-card-hover: #1f2b3f;
  --border: #2a3a50;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #38bdf8;
  --accent-dim: #0c4a6e;
  --red: #f87171;
  --red-dim: rgba(248, 113, 113, 0.12);
  --orange: #fb923c;
  --orange-dim: rgba(251, 146, 60, 0.12);
  --yellow: #facc15;
  --yellow-dim: rgba(250, 204, 21, 0.12);
  --green: #4ade80;
  --green-dim: rgba(74, 222, 128, 0.12);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Layout */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 80px 0;
}

section + section {
  border-top: 1px solid var(--border);
}

/* Typography */
h1, h2, h3, h4 { font-weight: 600; line-height: 1.3; }

h1 { font-size: 2.5rem; letter-spacing: -0.02em; }
h2 { font-size: 1.75rem; letter-spacing: -0.01em; margin-bottom: 12px; }
h3 { font-size: 1.125rem; }

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 8px;
}

.section-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 640px;
  margin-bottom: 40px;
}

/* Navigation */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-brand {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-brand span {
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero */
.hero {
  padding: 140px 0 80px;
  text-align: center;
}

.hero h1 {
  margin-bottom: 16px;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--accent), #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 32px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: #7dd3fc;
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
}

/* Cards Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  transition: border-color 0.2s, background 0.2s;
}

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

.card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.card h3 {
  margin-bottom: 8px;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Violation type colors */
.violation-smoking .card-icon { background: var(--red-dim); color: var(--red); }
.violation-phone .card-icon { background: var(--orange-dim); color: var(--orange); }
.violation-umbrella .card-icon { background: var(--yellow-dim); color: var(--yellow); }

/* Pipeline flow */
.pipeline-flow {
  display: flex;
  gap: 0;
  align-items: stretch;
  overflow-x: auto;
  padding-bottom: 8px;
}

.pipeline-step {
  flex: 1;
  min-width: 200px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 24px 20px;
  position: relative;
}

.pipeline-step:first-child { border-radius: 12px 0 0 12px; }
.pipeline-step:last-child { border-radius: 0 12px 12px 0; }

.pipeline-step + .pipeline-step {
  border-left: none;
}

.pipeline-step::after {
  content: '';
  position: absolute;
  right: -1px;
  top: 50%;
  transform: translateY(-50%);
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-left: 10px solid var(--border);
  z-index: 1;
}

.pipeline-step:last-child::after { display: none; }

.step-num {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.pipeline-step h3 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.pipeline-step p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* Demo section */
.demo-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.demo-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}

.demo-tab {
  padding: 8px 16px;
  border-radius: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}

.demo-tab.active {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent);
}

.demo-tab:hover:not(.active) {
  background: var(--bg-card-hover);
}

.video-placeholder {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  flex-direction: column;
  gap: 8px;
  position: relative;
  overflow: hidden;
}

.video-placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.03), rgba(129, 140, 248, 0.03));
}

.demo-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 16px;
  align-items: start;
}

@media (max-width: 1024px) {
  .demo-layout {
    grid-template-columns: 1fr;
  }
}

.demo-right .event-log {
  position: sticky;
  top: 80px;
}

.video-container {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
}

.demo-video {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 12px;
  background: #000;
}

.event-item {
  cursor: pointer;
  transition: background 0.15s;
}

.event-item:hover {
  background: rgba(56, 189, 248, 0.08);
}

/* Event log */
.event-log {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.event-log-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.event-count {
  background: var(--accent-dim);
  color: var(--accent);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.7rem;
}

.event-list {
  max-height: 600px;
  overflow-y: auto;
}

.event-item {
  padding: 10px 16px;
  border-bottom: 1px solid rgba(42, 58, 80, 0.5);
  font-size: 0.8rem;
  cursor: pointer;
  transition: background 0.15s;
}

.event-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: center;
}

.event-item:hover {
  background: var(--bg-card-hover);
}

.event-item:last-child {
  border-bottom: none;
}

.event-snapshot-wrapper {
  margin-top: 8px;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--border);
  max-width: 280px;
}

.event-snapshot {
  width: 100%;
  display: block;
  border-radius: 6px;
}

.vlm-eval {
  margin-top: 6px;
  padding: 6px 10px;
  background: rgba(56, 189, 248, 0.06);
  border-radius: 6px;
  font-size: 0.72rem;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 6px;
}

.vlm-icon { font-size: 0.8rem; }
.vlm-label { font-weight: 600; color: var(--accent); white-space: nowrap; }
.vlm-desc { line-height: 1.4; }

.event-badge {
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 0.7rem;
  font-weight: 600;
  white-space: nowrap;
}

.event-badge.walking_smoking {
  background: var(--red-dim);
  color: var(--red);
}

.event-badge.bicycle_phone {
  background: var(--orange-dim);
  color: var(--orange);
}

.event-badge.bicycle_umbrella {
  background: var(--yellow-dim);
  color: var(--yellow);
}

.event-badge.walking_phone {
  background: rgba(96, 165, 250, 0.15);
  color: #60a5fa;
}

.event-badge.bicycle_wrong_way {
  background: rgba(232, 121, 249, 0.15);
  color: #e879f9;
}

.event-badge.signal_violation {
  background: rgba(248, 113, 113, 0.15);
  color: #f87171;
}

.event-badge.sidewalk_riding {
  background: rgba(34, 211, 238, 0.15);
  color: #22d3ee;
}

.event-info {
  color: var(--text-secondary);
}

.event-info strong {
  color: var(--text-primary);
  font-weight: 500;
}

.event-conf {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

/* JSON preview */
.json-preview {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.json-header {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.json-body {
  padding: 16px;
  overflow-x: auto;
}

.json-body pre {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

.json-body .json-key { color: #7dd3fc; }
.json-body .json-string { color: #86efac; }
.json-body .json-number { color: #fbbf24; }

/* Roadmap */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.roadmap-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}

.roadmap-item h4 {
  font-size: 0.9rem;
  margin-bottom: 6px;
}

.roadmap-item p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.roadmap-status {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}

.status-done { color: var(--green); }
.status-next { color: var(--accent); }
.status-planned { color: var(--text-muted); }

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

/* Responsive */
@media (max-width: 768px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.375rem; }

  section { padding: 48px 0; }

  .hero { padding: 100px 0 48px; }

  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    gap: 12px;
  }
  .nav-toggle { display: block; }

  .pipeline-flow {
    flex-direction: column;
  }

  .pipeline-step {
    border-radius: 0 !important;
    border-left: 1px solid var(--border) !important;
  }

  .pipeline-step::after {
    right: 50%;
    top: auto;
    bottom: -10px;
    transform: translateX(50%) rotate(90deg);
  }

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

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Timeline */
.timeline {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-top: 16px;
}

.timeline-bar {
  position: relative;
  height: 32px;
  background: var(--bg-secondary);
  border-radius: 6px;
  overflow: hidden;
  cursor: pointer;
}

.timeline-event {
  position: absolute;
  top: 4px;
  height: 24px;
  border-radius: 4px;
  opacity: 0.85;
  transition: opacity 0.15s;
  cursor: pointer;
}

.timeline-event:hover {
  opacity: 1;
}

.timeline-event.walking_smoking { background: var(--red); }
.timeline-event.bicycle_phone { background: var(--orange); }
.timeline-event.bicycle_umbrella { background: var(--yellow); }
.timeline-event.walking_phone { background: #60a5fa; }
.timeline-event.bicycle_wrong_way { background: #e879f9; }
.timeline-event.signal_violation { background: #f87171; }
.timeline-event.sidewalk_riding { background: #22d3ee; }

.timeline-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 6px;
  font-size: 0.7rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.timeline-legend {
  display: flex;
  gap: 16px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 3px;
}

.legend-dot.walking_smoking { background: var(--red); }
.legend-dot.bicycle_phone { background: var(--orange); }
.legend-dot.bicycle_umbrella { background: var(--yellow); }
.legend-dot.walking_phone { background: #60a5fa; }
.legend-dot.bicycle_wrong_way { background: #e879f9; }
.legend-dot.signal_violation { background: #f87171; }
.legend-dot.sidewalk_riding { background: #22d3ee; }

/* Event Filters */
.event-filters {
  display: flex;
  gap: 6px;
  padding: 8px 16px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border);
}

.filter-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 4px 10px;
  border-radius: 14px;
  font-size: 0.72rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

.filter-btn:hover { border-color: var(--accent); color: var(--accent); }
.filter-btn.active { background: var(--accent); color: #000; border-color: var(--accent); }

/* Stats Summary */
.stats-summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-top: 16px;
  overflow: hidden;
}

.stats-header {
  padding: 12px 16px;
  font-weight: 600;
  font-size: 0.85rem;
  border-bottom: 1px solid var(--border);
}

.stats-body {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  background: var(--border);
}

.stat-card {
  background: var(--surface);
  padding: 16px;
  text-align: center;
}

.stat-value {
  font-size: 1.8rem;
  font-weight: 700;
  line-height: 1;
}

.stat-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.stat-value.walking_smoking { color: var(--red); }
.stat-value.bicycle_phone { color: var(--orange); }
.stat-value.bicycle_umbrella { color: var(--yellow); }
.stat-value.walking_phone { color: #60a5fa; }
.stat-value.bicycle_wrong_way { color: #e879f9; }
.stat-value.signal_violation { color: #f87171; }
.stat-value.sidewalk_riding { color: #22d3ee; }

/* Heatmap */
.heatmap-container {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin-bottom: 16px;
}

.heatmap-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.75rem;
  color: var(--text-secondary);
  justify-content: center;
}