:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #5a5a5a;
  --link: #1a56db;
  --border: #e5e5e5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --text: #ececec;
    --muted: #a8a8a8;
    --link: #7aa7ff;
    --border: #2c2c2c;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
main { max-width: 760px; margin: 0 auto; padding: 48px 20px 64px; }
header { border-bottom: 1px solid var(--border); padding-bottom: 16px; margin-bottom: 32px; }
header a.brand { font-weight: 700; font-size: 18px; color: var(--text); text-decoration: none; }
nav { margin-top: 8px; display: flex; gap: 16px; flex-wrap: wrap; font-size: 14px; }
h1 { font-size: 30px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 21px; margin: 36px 0 8px; }
h3 { font-size: 17px; margin: 24px 0 4px; }
p, li { color: var(--text); }
.muted { color: var(--muted); font-size: 14px; }
a { color: var(--link); }
footer { border-top: 1px solid var(--border); margin-top: 48px; padding-top: 16px; font-size: 14px; color: var(--muted); }