:root{font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;color:#17212e;background:#f7f8fa;line-height:1.65}
*{box-sizing:border-box}body{margin:0}header{background:#12263a;color:white;padding:16px 24px}
nav{max-width:840px;margin:auto;display:flex;gap:22px;flex-wrap:wrap}nav a{color:#e7f1ff;text-decoration:none}
main{max-width:840px;margin:44px auto;background:white;padding:44px;border:1px solid #e2e6eb;border-radius:14px}
h1{line-height:1.2;font-size:2rem}h2{margin-top:1.75em;font-size:1.25rem;color:#142f48}
a{color:#0053a6}p,li{max-width:75ch}footer{max-width:840px;margin:24px auto 45px;padding:0 14px;color:#4b5563;font-size:.9rem}
.note{background:#f0f4f8;padding:16px;border-radius:8px}code{background:#f1f3f5;padding:.14em .3em;border-radius:4px}
@media(max-width:700px){main{margin:12px;padding:24px;border-radius:0}h1{font-size:1.6rem}}