body{margin:0;background:#f4f7f8;color:#17353e;font:16px/1.7 system-ui,sans-serif}main{max-width:850px;margin:40px auto;padding:28px;background:white;border:1px solid #dce6eb;border-radius:16px}a{color:#137b60}h1{line-height:1.2}h2{font-size:20px;margin-top:28px}.muted{color:#657d85;font-size:13px}nav{display:flex;gap:18px;flex-wrap:wrap}@media(max-width:600px){main{margin:12px;padding:20px}}