:root { --bg: #ffffff; --fg: #1b1d21; --muted: #5d636e; --line: #e3e5e8; --link: #2556c9; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #15171a; --fg: #e8eaed; --muted: #a0a6b0; --line: #2c3036; --link: #8fb0ff; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.6 system-ui, -apple-system, "Segoe UI", sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 48px 16px 64px; }
header { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; flex-wrap: wrap;
  padding-bottom: 16px; border-bottom: 1px solid var(--line); margin-bottom: 32px; }
header a.brand { font-weight: 700; font-size: 20px; color: var(--fg); text-decoration: none; }
nav a { margin-left: 16px; }
nav a:first-child { margin-left: 0; }
h1 { font-size: 30px; line-height: 1.25; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 32px 0 8px; }
p, li { color: var(--fg); }
.muted { color: var(--muted); }
a { color: var(--link); }
ul { padding-left: 20px; }
footer { margin-top: 48px; padding-top: 16px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }