body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;margin:0;padding:0;line-height:1.5;background:#fff;color:#111}
.topbar{position:sticky;top:0;background:#f8f8f8;border-bottom:1px solid #ddd;padding:12px}
h1{margin:0 0 8px 0;font-size:20px}
nav a{margin-right:12px;text-decoration:none;color:#0a58ca}
main{padding:16px}
.card{border:1px solid #ddd;border-radius:10px;padding:12px;margin:10px 0;box-shadow:0 1px 3px rgba(0,0,0,.05)}
pre{white-space:pre-wrap}
code{background:#f0f0f0;padding:2px 6px;border-radius:6px}
footer{padding:16px;color:#666;border-top:1px solid #eee}