:root { --bg: #ffffff; --fg: #1a1a1a; --muted: #4a4a4a; --link: #0b5cad; --rule: #cfcfcf; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #14171a; --fg: #ececec; --muted: #b5b5b5; --link: #7db7ff; --rule: #3a3f45; }
}
body { background: var(--bg); color: var(--fg); font: 1.05rem/1.6 system-ui, sans-serif;
       max-width: 42rem; margin: 0 auto; padding: 1rem; }
a { color: var(--link); }
h1, h2 { line-height: 1.25; }
h2 { margin-top: 2rem; border-top: 1px solid var(--rule); padding-top: 1rem; }
footer { margin-top: 3rem; color: var(--muted); font-size: .95rem; }
nav a { margin-right: 1rem; }