:root { --fg:#1b1f23; --muted:#57606a; --bg:#ffffff; --accent:#0b6e4f; --line:#d8dee4; }
@media (prefers-color-scheme: dark) { :root { --fg:#e6edf3; --muted:#9da7b3; --bg:#0d1117; --accent:#3fb98a; --line:#30363d; } }
* { box-sizing: border-box; }
body { margin:0; background:var(--bg); color:var(--fg); font:16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
main { max-width: 42rem; margin: 0 auto; padding: 2rem 1rem 4rem; }
h1 { font-size: 1.8rem; margin-bottom: .25rem; }
h2 { font-size: 1.2rem; margin-top: 2rem; border-top: 1px solid var(--line); padding-top: 1rem; }
a { color: var(--accent); }
.muted { color: var(--muted); }
nav a { margin-right: 1rem; }