:root {
  --bg: #ffffff;
  --fg: #1b2430;
  --muted: #5a6677;
  --accent: #1f5fbf;
  --line: #dde3ea;
  --soft: #f4f7fb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1620;
    --fg: #e6ebf2;
    --muted: #9aa7b8;
    --accent: #6ea8ff;
    --line: #243040;
    --soft: #16202c;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
header, main, footer { max-width: 46rem; margin: 0 auto; padding: 0 1rem; }
header { display: flex; justify-content: space-between; align-items: center; padding-top: 1.25rem; padding-bottom: 1.25rem; border-bottom: 1px solid var(--line); }
header .brand { font-weight: 700; font-size: 1.15rem; color: var(--fg); text-decoration: none; }
header nav a { margin-left: 1rem; font-size: 0.95rem; }
main { padding-top: 2rem; padding-bottom: 3rem; }
h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 0.5rem; }
h2 { font-size: 1.25rem; margin: 2rem 0 0.5rem; }
.lede { font-size: 1.15rem; color: var(--muted); margin-top: 0; }
.muted { color: var(--muted); font-size: 0.9rem; }
.card { background: var(--soft); border: 1px solid var(--line); border-radius: 8px; padding: 1rem 1.25rem; margin: 1.5rem 0; }
.sample { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.95rem; }
ul { padding-left: 1.25rem; }
footer { border-top: 1px solid var(--line); padding-top: 1.25rem; padding-bottom: 2rem; color: var(--muted); font-size: 0.9rem; }
footer a { margin-right: 1rem; }