:root{--bg:#f6fbfc;--fg:#1f2a30;--muted:#5a6b73;--accent:#1f9fab;--card:#fff;--line:#dbe7ea}
@media (prefers-color-scheme:dark){:root{--bg:#0f1719;--fg:#e6eef0;--muted:#9fb1b7;--accent:#45bdc6;--card:#172225;--line:#26363a}}
*{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:760px;margin:0 auto;padding:32px 16px 64px}h1{font-size:28px;margin:0 0 4px}h2{font-size:19px;margin:28px 0 8px}
.muted{color:var(--muted)}a{color:var(--accent)}.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px 20px;margin:16px 0}
nav a{margin-right:16px}ul,ol{padding-left:20px}