:root {
  --bg: #f6f7f9;
  --fg: #1c2330;
  --muted: #5d6778;
  --card: #fff;
  --border: #dde1e8;
  --accent: #2f5fd0;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161d;
    --fg: #e8ebf0;
    --muted: #98a2b3;
    --card: #1b212b;
    --border: #2d3544;
    --accent: #7ea2ff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}
main { max-width: 720px; margin: 0 auto; padding: 64px 16px; }
h1 { margin: 0 0 4px; font-size: 2rem; }
.lede { margin: 0 0 32px; color: var(--muted); }
nav { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card {
  display: block;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: inherit;
  text-decoration: none;
}
.card:hover, .card:focus-visible { border-color: var(--accent); outline: none; }
.card h2 { margin: 0 0 4px; font-size: 1.15rem; color: var(--accent); }
.card p { margin: 0; color: var(--muted); }