*{box-sizing:border-box}body{margin:0;background:#f5f7fc;color:#172842;font-family:system-ui,-apple-system,"Noto Sans JP",sans-serif;line-height:1.9;overflow-wrap:anywhere}header,footer{max-width:960px;margin:auto;padding:24px}header img{max-width:100%;height:auto}main{max-width:912px;margin:0 auto;background:#fff;border:1px solid #dbe3f1;border-radius:16px;padding:40px}h1{font-size:clamp(24px,4vw,32px);line-height:1.5;margin:0 0 12px}h2{font-size:20px;line-height:1.6;margin:32px 0 12px}p{margin:12px 0}.updated{color:#53647c}a{color:#1855a0;text-underline-offset:3px}a:focus-visible{outline:3px solid #375eff;outline-offset:4px}nav{display:flex;gap:12px 24px;flex-wrap:wrap}footer{font-size:14px}dt{font-weight:700;margin-top:24px}dd{margin:6px 0 0;padding-bottom:20px;border-bottom:1px solid #e4e9f2}@media(max-width:600px){main{margin:0 12px;padding:24px 20px}header,footer{padding:20px}body{font-size:16px}}