:root{font-family:system-ui,'Yu Gothic',sans-serif;color:#172c36;background:#f5f8fa;font-size:16px}*{box-sizing:border-box}body{margin:0}header,main,footer{max-width:860px;margin:auto;padding:24px}header{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #cbd9e0;gap:16px}a{color:#006779;text-underline-offset:4px}nav{display:flex;gap:20px;flex-wrap:wrap}main{padding-top:48px;padding-bottom:64px;line-height:1.85}h1{font-size:2.3rem;line-height:1.3;margin:0 0 24px}h2{font-size:1.35rem;line-height:1.4;margin:32px 0 12px}p{margin:12px 0}.brand{font-weight:750;text-decoration:none;color:#172c36}.tag{color:#006779;font-weight:700}.card{background:white;border:1px solid #cbd9e0;border-radius:12px;padding:24px;margin:24px 0}footer{border-top:1px solid #cbd9e0;font-size:.9rem;color:#475d68}@media(max-width:600px){header{align-items:flex-start;flex-direction:column}main{padding-top:32px}h1{font-size:1.9rem}nav{gap:14px}}