body{margin:0;background:#fff;color:#18212f;font-family:system-ui,'Microsoft YaHei',sans-serif;line-height:1.8}main{max-width:720px;margin:64px auto;padding:0 24px}h1{font-size:2rem;line-height:1.3;margin:40px 0 24px}h2{font-size:1.25rem;margin:32px 0 12px}p{margin:12px 0}a{color:#0867d8;text-underline-offset:4px}a:focus-visible{outline:2px solid #0867d8;outline-offset:4px}::selection{background:#eaf2ff}@media(max-width:600px){main{margin:32px auto}}