:root { --text: #1f2328; --muted: #57606a; --line: #d8dee4; --bg: #ffffff; --box: #f3f5f7; --accent: #1a5c45; }
@media (prefers-color-scheme: dark) {
  :root { --text: #e6edf3; --muted: #9aa5b1; --line: #30363d; --bg: #0d1117; --box: #161b22; --accent: #3fb68b; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.6 system-ui, -apple-system, "Segoe UI", sans-serif; }
main { max-width: 42rem; margin: 0 auto; padding: 2.5rem 16px 4rem; }
h1 { font-size: 1.6rem; margin: 0 0 .25rem; }
h2 { font-size: 1.1rem; margin: 1.8rem 0 .4rem; }
p, li { margin: .4rem 0; }
.muted { color: var(--muted); }
a { color: var(--accent); }
nav { display: flex; gap: 1.2rem; padding-top: 1.5rem; margin-top: 2rem; border-top: 1px solid var(--line); font-size: .95rem; }
code.big { display: block; padding: .9rem; background: var(--box); border: 1px solid var(--line); border-radius: 6px;
           font-size: 1.05rem; word-break: break-all; margin: 1rem 0; }
button { font: inherit; padding: .55rem 1.1rem; border-radius: 6px; border: 1px solid var(--accent);
         background: var(--accent); color: #fff; cursor: pointer; }