:root{--bg:#fff;--fg:#1d2430;--muted:#5b6575;--brand:#2d7ff9;--line:#e3e8ef}
@media (prefers-color-scheme:dark){:root{--bg:#10141b;--fg:#e8ecf3;--muted:#9aa5b8;--line:#232b38}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
main{max-width:720px;margin:0 auto;padding:40px 20px 80px}
h1{font-size:2rem;margin:.2em 0 .1em}h2{font-size:1.15rem;margin:2em 0 .4em}
p,li{color:var(--fg)}.muted{color:var(--muted)}a{color:var(--brand)}
header{border-bottom:1px solid var(--line)}header div{max-width:720px;margin:0 auto;padding:14px 20px;font-weight:700}
footer{border-top:1px solid var(--line);color:var(--muted);font-size:.9rem}footer div{max-width:720px;margin:0 auto;padding:20px}