:root {
  --bg: #0d1117;
  --panel: #111827;
  --ink: #cbd5e1;
  --muted: #8b949e;
  --accent: #58a6ff;
  --grid: #1f2937;
  --card: #0f172a;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
}
header {
  padding: 16px 24px; border-bottom: 1px solid var(--grid);
  position: sticky; top: 0; background: rgba(13,17,23,0.9); backdrop-filter: blur(8px); z-index: 10;
}
.title { font-size: 18px; font-weight: 600; }
.subtitle { color: var(--muted); margin-top: 4px; font-size: 13px; }
.container { max-width: 1400px; margin: 0 auto; padding: 16px 24px 64px; }
.card {
  background: linear-gradient(180deg, var(--panel), var(--card));
  border: 1px solid var(--grid); border-radius: 12px; padding: 16px 20px; margin-bottom: 16px;
}
h2, h3 { margin: 0 0 8px 0; font-weight: 600; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(540px, 1fr)); gap: 16px; }
canvas { display: block; image-rendering: auto; }