body{margin:0;background:#f5f7fb;color:#172238;font:17px/1.7 system-ui,sans-serif}main{max-width:850px;margin:60px auto;padding:40px;background:white;border-radius:20px}nav{display:flex;gap:24px;flex-wrap:wrap;border-bottom:1px solid #ddd;padding-bottom:20px}a{color:#2755a8}h1{font-size:40px;line-height:1.2}h2{font-size:24px;margin-top:32px}.tag{color:#50617d;font-size:14px;letter-spacing:2px}footer{margin-top:40px;padding-top:20px;border-top:1px solid #ddd;font-size:14px}@media(max-width:600px){main{margin:16px;padding:24px}h1{font-size:32px}}