:root {
  --bg: #0f1720;
  --panel: #18222e;
  --panel-2: #1f2b39;
  --text: #e6edf3;
  --muted: #9fb0c3;
  --accent: #4fc3f7;
  --accent-2: #ffb74d;
  --road: #2b3644;
  --road-edge: #3b4a5c;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  min-height: 100vh;
}

header {
  padding: 24px 24px 8px;
  text-align: center;
}

header h1 {
  margin: 0 0 6px;
  font-size: 1.6rem;
  letter-spacing: 0.3px;
}

.subtitle {
  margin: 0 auto;
  max-width: 720px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.5;
}

.subtitle a { color: var(--accent); }

main {
  display: grid;
  grid-template-columns: minmax(320px, 1fr) 320px;
  gap: 20px;
  padding: 20px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

@media (max-width: 900px) {
  main { grid-template-columns: 1fr; }
}

.stage {
  background: var(--panel);
  border-radius: 12px;
  padding: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 4px 14px rgba(0,0,0,0.3);
}

.stage canvas {
  width: 100%;
  height: auto;
  max-width: 720px;
  aspect-ratio: 1 / 1;
  display: block;
  background: radial-gradient(circle at 50% 50%, #1a2532 0%, #0e1620 75%);
  border-radius: 8px;
}

.controls {
  background: var(--panel);
  border-radius: 12px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: 0 4px 14px rgba(0,0,0,0.3);
}

.control label {
  display: block;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 4px;
}

.control label span {
  color: var(--text);
  font-weight: 600;
  float: right;
}

.control input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

button {
  flex: 1 1 auto;
  padding: 8px 10px;
  font-size: 0.88rem;
  border: 1px solid #2e3d4f;
  border-radius: 6px;
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}

button:hover { background: #26384b; }
button:active { transform: translateY(1px); }

#perturb { border-color: var(--accent-2); color: var(--accent-2); }

.stats {
  margin-top: 8px;
  padding: 10px 12px;
  background: var(--panel-2);
  border-radius: 8px;
  font-size: 0.88rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px 14px;
}

.stats span { color: var(--muted); }
.stats strong { color: var(--accent); font-variant-numeric: tabular-nums; }

footer {
  text-align: center;
  padding: 16px;
  color: var(--muted);
  font-size: 0.85rem;
}

.charts {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 24px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.chart-card {
  background: var(--panel);
  border-radius: 12px;
  padding: 12px 14px;
  box-shadow: 0 4px 14px rgba(0,0,0,0.3);
}

.chart-card.chart-wide { grid-column: 1 / -1; }

.chart-card h3 {
  margin: 0 0 8px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
}

.chart-card h3 .unit {
  color: var(--muted);
  font-weight: 400;
  font-size: 0.82rem;
  margin-left: 4px;
}

.chart-card canvas {
  width: 100%;
  height: auto;
  display: block;
  background: #0e1620;
  border-radius: 6px;
}

@media (max-width: 900px) {
  .charts { grid-template-columns: 1fr; }
}

footer a { color: var(--accent); }

.gp-group {
  margin-top: 6px;
  padding: 10px 12px;
  background: rgba(255,183,77,0.05);
  border: 1px solid rgba(255,183,77,0.25);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.gp-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-2);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.gp-title a {
  width: 18px; height: 18px; line-height: 18px;
  text-align: center;
  border-radius: 50%;
  background: rgba(255,183,77,0.2);
  color: var(--accent-2);
  font-size: 0.75rem;
  text-decoration: none;
}

.gp-group select {
  width: 100%;
  padding: 6px 8px;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid #2e3d4f;
  border-radius: 6px;
  font-size: 0.88rem;
}

.hint {
  font-size: 0.78rem;
  color: rgba(230,237,243,0.6);
  line-height: 1.4;
}
.hint a { color: var(--accent-2); }

.tribute {
  font-size: 0.85rem;
  color: rgba(230,237,243,0.65);
  font-style: italic;
  margin-top: 6px;
  padding: 8px 12px;
  border-left: 3px solid var(--accent-2);
  background: rgba(255,183,77,0.06);
  border-radius: 4px;
}

.fd-axes {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 4px 10px;
  align-items: center;
  margin-top: 8px;
  font-size: 0.78rem;
  color: rgba(230,237,243,0.65);
}
.fd-axes input[type="range"] { width: 100%; }

.stage canvas#road { cursor: crosshair; }

.tribute-small {
  font-size: 0.82rem;
  color: rgba(230,237,243,0.55);
  margin-top: 4px;
}

.about {
  margin: 24px auto 12px;
  max-width: 1200px;
  padding: 0 16px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.about-card {
  background: var(--panel);
  border: 1px solid #2a3645;
  border-radius: 10px;
  padding: 16px 20px;
}
.about-card h2 {
  margin: 0 0 10px 0;
  font-size: 1.05rem;
  color: var(--accent-2);
}
.about-card p { margin: 6px 0; font-size: 0.92rem; line-height: 1.5; }
.about-card a { color: var(--accent); }
.contact-links { font-size: 0.88rem; }
.refs { padding-left: 20px; font-size: 0.88rem; line-height: 1.55; }
.refs li { margin-bottom: 8px; }
.about-card details { margin-top: 8px; }
.about-card summary {
  cursor: pointer;
  font-size: 0.88rem;
  color: var(--accent-2);
  padding: 4px 0;
}
.about-card pre {
  background: var(--panel-2);
  border: 1px solid #2a3645;
  border-radius: 6px;
  padding: 10px 12px;
  font-size: 0.78rem;
  overflow-x: auto;
  white-space: pre;
}

.author-card .author {
  display: flex;
  gap: 14px;
  align-items: center;
  margin: 10px 0 14px;
}
.author-card .avatar {
  flex: 0 0 56px;
  width: 56px; height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0e1620;
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(79,195,247,0.25);
}
.author-card .author-name {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}
.author-card .author-affil {
  font-size: 0.85rem;
  color: rgba(230,237,243,0.65);
  line-height: 1.4;
  margin-top: 2px;
}
.author-card .author-email {
  font-size: 0.88rem;
  margin-top: 4px;
}
.author-card .author-email a { color: var(--accent); }

.contact-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.contact-chips .chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--panel-2);
  border: 1px solid #2e3d4f;
  border-radius: 999px;
  color: var(--text);
  font-size: 0.85rem;
  text-decoration: none;
  transition: border-color 0.15s, transform 0.15s, background 0.15s;
}
.contact-chips .chip:hover {
  border-color: var(--accent);
  background: rgba(79,195,247,0.1);
  transform: translateY(-1px);
}
.contact-chips .chip-icon {
  font-size: 0.95rem;
  line-height: 1;
}

@media (max-width: 800px) {
  .about { grid-template-columns: 1fr; }
}

/* ================= Top nav (shared) ================= */
.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 24px;
  background: rgba(24, 34, 46, 0.75);
  border-bottom: 1px solid #2b3644;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(6px);
}
.topnav-brand {
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.2px;
}
.topnav-links { display: flex; gap: 4px; }
.topnav-link {
  color: var(--muted);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 14px;
}
.topnav-link:hover { background: #1f2b39; color: var(--text); }
.topnav-link.active { background: #1f2b39; color: var(--accent); }

/* ================= Compare page ================= */
.cmp-controls {
  max-width: 1080px;
  margin: 12px auto 18px;
  padding: 14px 18px;
  background: var(--panel);
  border-radius: 10px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px 18px;
  align-items: end;
}
.cmp-controls .control { margin: 0; }
.cmp-controls .buttons {
  grid-column: 1 / -1;
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 4px;
}
.cmp-controls .hint { grid-column: 1 / -1; margin: 0; }

.cmp-rings {
  max-width: 1200px;
  margin: 0 auto 18px;
  padding: 0 18px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.cmp-ring {
  background: var(--panel);
  border-radius: 10px;
  padding: 12px;
  text-align: center;
}
.cmp-ring canvas {
  width: 100%;
  height: auto;
  max-width: 340px;
  display: block;
  margin: 0 auto;
  background: #0b1118;
  border-radius: 8px;
}
.cmp-label {
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 14px;
}
.cmp-stats {
  margin-top: 8px;
  font-size: 13px;
  color: var(--muted);
}
.cmp-stats strong { color: var(--text); margin: 0 4px; }

.cmp-charts {
  max-width: 1200px;
  margin: 0 auto 32px;
  padding: 0 18px;
  display: grid;
  gap: 16px;
}
.cmp-charts .chart-card canvas {
  width: 100%;
  height: auto;
  max-width: 100%;
}
.chart-cap {
  color: var(--muted);
  font-size: 12.5px;
  margin: 4px 0 10px;
}
.metrics-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
}
.metrics-table th,
.metrics-table td {
  padding: 8px 10px;
  text-align: center;
  border-bottom: 1px solid #273244;
}
.metrics-table th { color: var(--muted); font-weight: 600; }
.metrics-table td:first-child { text-align: left; color: var(--muted); }
.metrics-table tbody tr:last-child td { border-bottom: none; }

@media (max-width: 800px) {
  .cmp-rings { grid-template-columns: 1fr; }
}