/* ============ base ============ */
:root {
  --bg: #0a0f1e;
  --bg-alt: #0f172a;
  --panel: #141d33;
  --panel-2: #1a2542;
  --ink: #e8ecf7;
  --ink-dim: #9aa6c2;
  --ink-faint: #6b7794;
  --accent: #3b82f6;
  --accent-2: #60a5fa;
  --accent-3: #a78bfa;
  --warm: #f59e0b;
  --line: rgba(148, 163, 184, 0.14);
  --line-strong: rgba(148, 163, 184, 0.28);
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.6);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
code, pre { font-family: 'JetBrains Mono', ui-monospace, monospace; }
a { color: var(--accent-2); text-decoration: none; }
a:hover { color: var(--accent); }
img { display: block; max-width: 100%; }

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

/* ============ nav ============ */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 15, 30, 0.7);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1180px; margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--ink); letter-spacing: -0.01em; }
.brand-x { color: var(--accent-2); margin: 0 4px; font-weight: 400; }
.logo-dot {
  width: 18px; height: 18px; border-radius: 50%;
  background: conic-gradient(from 180deg, #f59e0b, #3b82f6, #a78bfa, #f59e0b);
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.6);
}
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--ink-dim); font-size: 14px; font-weight: 500; }
.nav-links a:hover { color: var(--ink); }
.nav-cta {
  padding: 8px 14px; border-radius: 999px;
  background: var(--accent); color: #fff !important;
  font-weight: 600;
}
.nav-cta:hover { background: var(--accent-2); }
@media (max-width: 780px) {
  .nav-links a:not(.nav-cta) { display: none; }
}

/* ============ hero ============ */
.hero {
  position: relative; overflow: hidden;
  padding: 100px 0 90px;
  border-bottom: 1px solid var(--line);
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(900px 500px at 15% 10%, rgba(59, 130, 246, 0.22), transparent 60%),
    radial-gradient(700px 400px at 90% 20%, rgba(167, 139, 250, 0.16), transparent 60%),
    radial-gradient(600px 400px at 50% 100%, rgba(245, 158, 11, 0.10), transparent 60%);
  pointer-events: none;
}
.hero-inner { position: relative; }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; }
.badge {
  font-size: 12px; font-weight: 600; letter-spacing: 0.02em;
  padding: 6px 12px; border-radius: 999px;
  background: rgba(148, 163, 184, 0.08);
  color: var(--ink-dim);
  border: 1px solid var(--line-strong);
}
.badge-ijcai { background: rgba(59, 130, 246, 0.14); color: var(--accent-2); border-color: rgba(59,130,246,0.35); }
.badge-kdd   { background: rgba(167, 139, 250, 0.14); color: var(--accent-3); border-color: rgba(167,139,250,0.35); }

.hero h1 {
  font-size: clamp(38px, 5.4vw, 68px);
  line-height: 1.05; letter-spacing: -0.025em;
  font-weight: 800; margin: 0 0 22px;
}
.grad {
  background: linear-gradient(135deg, #60a5fa 10%, #a78bfa 50%, #f59e0b 95%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lede {
  font-size: 18px; color: var(--ink-dim);
  max-width: 680px; margin: 0 0 34px;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 52px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 999px;
  font-weight: 600; font-size: 15px;
  border: 1px solid var(--line-strong);
  background: transparent; color: var(--ink);
  cursor: pointer; transition: all 0.15s;
}
.btn:hover { border-color: var(--accent); color: var(--accent-2); }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  border-color: transparent; color: #fff !important;
  box-shadow: 0 10px 30px -10px rgba(59, 130, 246, 0.6);
}
.btn-primary:hover { transform: translateY(-1px); color: #fff !important; }
.btn-small { padding: 8px 16px; font-size: 13px; }
.btn-ghost { background: rgba(148, 163, 184, 0.06); }

.hero-stats {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px;
  padding: 22px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  max-width: 760px;
}
.hero-stats > div { display: flex; flex-direction: column; gap: 2px; }
.hero-stats b {
  font-size: 28px; font-weight: 700; color: var(--ink);
  font-feature-settings: 'tnum';
}
.hero-stats span { font-size: 12px; color: var(--ink-faint); text-transform: uppercase; letter-spacing: 0.08em; }
@media (max-width: 640px) {
  .hero-stats { grid-template-columns: repeat(3, 1fr); }
  .hero-stats > div:nth-child(4), .hero-stats > div:nth-child(5) { }
}

/* ============ sections ============ */
.section { padding: 100px 0; border-bottom: 1px solid var(--line); }
.section-alt { background: var(--bg-alt); }
.section-head { max-width: 720px; margin: 0 auto 48px; text-align: center; }
.eyebrow {
  display: inline-block; font-size: 12px; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--accent-2); margin-bottom: 14px;
}
.section h2 {
  font-size: clamp(28px, 3.6vw, 44px); line-height: 1.1;
  letter-spacing: -0.02em; margin: 0 0 16px; font-weight: 700;
}
.section-head p { color: var(--ink-dim); font-size: 16px; margin: 0; }

/* ============ demo card ============ */
.demo-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow);
}
.demo-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 22px; border-bottom: 1px solid var(--line);
  background: var(--panel-2);
}
.city-picker { display: flex; align-items: center; gap: 12px; }
.city-picker label { font-size: 12px; color: var(--ink-faint); text-transform: uppercase; letter-spacing: 0.08em; }
.city-picker select {
  background: var(--bg); color: var(--ink);
  border: 1px solid var(--line-strong); border-radius: 8px;
  padding: 8px 12px; font-family: inherit; font-size: 14px;
  cursor: pointer;
}
.time-readout { text-align: right; }
.time-value { font-size: 26px; font-weight: 700; letter-spacing: -0.02em; font-feature-settings: 'tnum'; }
.sun-meta { font-size: 12px; color: var(--ink-faint); font-family: 'JetBrains Mono', monospace; }

.demo-stage {
  position: relative; aspect-ratio: 1 / 1;
  background: #020617 center/cover no-repeat;
  max-height: 640px;
}
.demo-stage img {
  width: 100%; height: 100%; object-fit: cover;
  transition: opacity 0.2s;
}
.sun-path {
  position: absolute; top: 16px; left: 16px; right: 16px; height: 60px;
  pointer-events: none;
}
.sun-path::before {
  content: ''; position: absolute; top: 50%; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(245, 158, 11, 0.5), transparent);
}
.sun-dot {
  position: absolute; top: 50%; width: 14px; height: 14px; border-radius: 50%;
  background: var(--warm); box-shadow: 0 0 20px rgba(245, 158, 11, 0.9);
  transform: translate(-50%, -50%); transition: left 0.25s ease, top 0.25s ease;
}
.sun-compass {
  position: absolute; top: 50%; transform: translateY(-50%);
  font-size: 11px; font-weight: 700; letter-spacing: 0.1em;
  color: rgba(245, 158, 11, 0.9);
  text-shadow: 0 1px 4px rgba(0,0,0,0.8);
  font-family: 'JetBrains Mono', monospace;
}
.sun-w { left: -2px; }
.sun-e { right: -2px; }

.demo-controls { padding: 22px; }
#timeSlider, input[type="range"] {
  width: 100%;
  -webkit-appearance: none; appearance: none;
  background: transparent;
  height: 30px;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 6px; border-radius: 999px;
  background: linear-gradient(90deg, #f59e0b, #3b82f6, #1e1b4b);
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  margin-top: -7px;
  width: 20px; height: 20px; border-radius: 50%;
  background: #fff; border: 3px solid var(--accent);
  cursor: pointer; box-shadow: 0 4px 12px rgba(0,0,0,0.4);
}
input[type="range"]::-moz-range-track { height: 6px; border-radius: 999px; background: linear-gradient(90deg, #f59e0b, #3b82f6, #1e1b4b); }
input[type="range"]::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%;
  background: #fff; border: 3px solid var(--accent);
  cursor: pointer;
}
.tick-row {
  display: flex; justify-content: space-between;
  font-size: 11px; color: var(--ink-faint); font-family: 'JetBrains Mono', monospace;
  margin-top: 4px; padding: 0 4px;
}
#playBtn { margin-bottom: 12px; }

/* ============ city grid ============ */
.city-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: 14px;
}
.city-card {
  position: relative; aspect-ratio: 1 / 1; border-radius: var(--radius-sm);
  overflow: hidden; cursor: pointer;
  background: var(--panel);
  border: 1px solid var(--line);
  transition: transform 0.2s, border-color 0.2s;
}
.city-card:hover { transform: translateY(-2px); border-color: var(--accent); }
.city-card img { width: 100%; height: 100%; object-fit: cover; opacity: 0.75; transition: opacity 0.2s; }
.city-card:hover img { opacity: 1; }
.city-card .city-tag {
  position: absolute; left: 10px; bottom: 10px; right: 10px;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; font-weight: 600;
}
.city-card .city-name { text-transform: capitalize; text-shadow: 0 2px 8px rgba(0,0,0,0.7); }
.city-card .city-flag { font-size: 16px; }
.city-card .city-gradient {
  position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(10,15,30,0.92) 0%, rgba(10,15,30,0) 45%);
}

/* Coming-soon placeholder cards */
.city-card-soon {
  cursor: not-allowed;
  background:
    repeating-linear-gradient(
      45deg,
      rgba(148, 163, 184, 0.04) 0 10px,
      rgba(148, 163, 184, 0.07) 10px 20px
    ),
    var(--panel);
  border-style: dashed;
}
.city-card-soon:hover { transform: none; border-color: var(--line-strong); }
.city-card-soon .city-name { color: var(--ink-dim); text-shadow: none; }
.city-card-soon .city-flag { opacity: 0.5; }
.soon-overlay {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
}
.soon-badge {
  font-size: 11px; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 6px 12px; border-radius: 999px;
  background: rgba(59, 130, 246, 0.12);
  color: var(--accent-2);
  border: 1px solid rgba(59, 130, 246, 0.3);
}
.gallery-note {
  text-align: center; margin-top: 28px; font-size: 14px;
  color: var(--ink-faint);
}
.gallery-note b { color: var(--ink); font-weight: 700; }

/* ============ compare ============ */
.compare-card {
  max-width: 900px; margin: 0 auto;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
}
.compare-tabs {
  display: flex; gap: 4px; padding: 12px;
  background: var(--panel-2); border-bottom: 1px solid var(--line);
}
.tab {
  flex: 1; padding: 10px 14px; border-radius: 8px;
  background: transparent; border: 1px solid transparent;
  color: var(--ink-dim); font-family: inherit; font-size: 13px; font-weight: 500;
  cursor: pointer; transition: all 0.15s;
}
.tab:hover { color: var(--ink); }
.tab.active { background: var(--bg); color: var(--ink); border-color: var(--line-strong); }

.compare-stage {
  position: relative; aspect-ratio: 1 / 1; max-height: 640px;
  background: #020617; overflow: hidden; user-select: none;
  cursor: ew-resize;
}
.compare-img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.compare-clip { clip-path: inset(0 0 0 50%); }
.compare-divider {
  position: absolute; top: 0; bottom: 0; left: 50%;
  width: 3px; background: #fff;
  box-shadow: 0 0 20px rgba(0,0,0,0.6);
  transform: translateX(-50%);
  pointer-events: none;
}
.compare-handle {
  position: absolute; top: 50%; left: 50%;
  width: 44px; height: 44px; border-radius: 50%;
  background: #fff; color: var(--bg);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 16px;
  transform: translate(-50%, -50%);
  box-shadow: 0 6px 20px rgba(0,0,0,0.5);
}
.compare-label {
  position: absolute; bottom: 14px;
  padding: 5px 10px; border-radius: 6px;
  background: rgba(10, 15, 30, 0.8); backdrop-filter: blur(8px);
  font-size: 12px; font-weight: 600; letter-spacing: 0.04em;
  color: var(--ink);
}
.compare-label.left  { left: 14px; }
.compare-label.right { right: 14px; }

/* ============ modalities ============ */
.modality-grid {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px;
}
@media (max-width: 900px) { .modality-grid { grid-template-columns: repeat(2, 1fr); } }
.modality-grid figure {
  margin: 0; background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius-sm); overflow: hidden;
}
.modality-grid img { aspect-ratio: 1; object-fit: cover; width: 100%; background: #020617; }
.modality-grid figcaption { padding: 14px; font-size: 13px; color: var(--ink-dim); line-height: 1.5; }
.modality-grid figcaption b { color: var(--ink); font-weight: 600; }

/* ============ results table ============ */
.table-wrap {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
}
.results-table { width: 100%; border-collapse: collapse; }
.results-table th, .results-table td {
  padding: 16px 22px; text-align: left; font-size: 14px;
  border-bottom: 1px solid var(--line);
}
.results-table th {
  background: var(--panel-2); color: var(--ink-faint);
  font-weight: 600; font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase;
}
.results-table td { color: var(--ink-dim); font-family: 'JetBrains Mono', monospace; }
.results-table td:first-child { color: var(--ink); font-family: inherit; }
.results-table tr.best td { background: rgba(59, 130, 246, 0.08); color: var(--ink); }
.results-table tr:last-child td { border-bottom: none; }
.caption { text-align: center; color: var(--ink-faint); font-size: 14px; margin-top: 20px; }

/* ============ code cards ============ */
.code-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
@media (max-width: 900px) { .code-grid { grid-template-columns: 1fr; } }
.code-card {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius-sm); overflow: hidden;
}
.code-title {
  padding: 14px 18px; font-size: 13px; font-weight: 600;
  color: var(--ink); background: var(--panel-2);
  border-bottom: 1px solid var(--line);
}
.code-card pre {
  margin: 0; padding: 18px; overflow-x: auto;
  font-size: 12.5px; line-height: 1.6; color: var(--ink-dim);
}
.code-card code { color: var(--accent-2); }

/* ============ footer ============ */
.footer {
  padding: 40px 0; background: var(--bg-alt);
  border-top: 1px solid var(--line);
}
.footer-inner {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 24px;
}
.footer-brand { font-weight: 700; color: var(--ink); }
.footer-sub { font-size: 13px; color: var(--ink-faint); margin-top: 4px; }
.footer-links { display: flex; gap: 20px; font-size: 14px; }