:root{--bg:#f6f8fb;--fg:#1d2533;--muted:#5d6b80;--accent:#2457a6;--line:#dde3ec}
@media (prefers-color-scheme:dark){:root{--bg:#141922;--fg:#e3e8f0;--muted:#97a3b6;--accent:#8db4f0;--line:#2b3445}}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.6 -apple-system,"Segoe UI",Roboto,Arial,sans-serif}
header,main,footer{max-width:50rem;margin:0 auto;padding:0 1rem}
header{display:flex;flex-wrap:wrap;gap:.4rem 1.4rem;align-items:center;padding:1rem;border-bottom:3px solid var(--accent)}
.brand{font-weight:700;letter-spacing:.02em;color:var(--accent);text-decoration:none}nav a{margin-right:1rem;color:var(--fg);text-decoration:none}
a{color:var(--accent)}h1{font-size:1.6rem;line-height:1.3}ol,ul{padding-left:1.3rem}ul.notes{list-style:none;padding:0}
ul.notes li{margin:0 0 1rem;padding:.8rem 1rem;background:var(--line);border-radius:6px}ul.notes p{margin:.3rem 0 0}
code{font-family:Menlo,Consolas,monospace;font-size:.9em}time{color:var(--muted);font-size:.85em;margin-left:.4rem}
footer{color:var(--muted);font-size:.85rem;padding:2rem 1rem;margin-top:2rem;border-top:1px solid var(--line)}