*,*::before,*::after{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;color:#1a1a1a;background:#fafafa;line-height:1.8;-webkit-font-smoothing:antialiased}
.wrap{max-width:720px;margin:0 auto;padding:2rem 1.5rem}
header{margin-bottom:2rem;padding-bottom:1.5rem;border-bottom:1px solid #e0e0e0}
h1{font-size:1.75rem;margin:0 0 .5rem;font-weight:700;line-height:1.3}
header p{color:#666;margin:.25rem 0;font-size:1rem}
.back{color:#4a90d9;text-decoration:none;font-size:.95rem}
.back:hover{text-decoration:underline}
main ol{list-style:none;counter-reset:item;padding:0;margin:0}
main ol li{counter-increment:item;padding:.6rem 0;border-bottom:1px solid #f0f0f0}
main ol li::before{content:counter(item) ". ";color:#999;font-size:.9rem;min-width:2rem;display:inline-block}
main ol li a{color:#1a1a1a;text-decoration:none}
main ol li a:hover{color:#4a90d9}
article{line-height:1.9;font-size:1.05rem}
article h1{font-size:1.6rem;margin-top:2rem}
article h2{font-size:1.35rem;margin-top:1.8rem}
article h3{font-size:1.15rem;margin-top:1.5rem}
article p{margin:.8rem 0}
article img{max-width:100%;height:auto;border-radius:4px}
article blockquote{margin:1rem 0;padding:.5rem 1rem;border-left:4px solid #4a90d9;background:#f5f8fc;color:#444}
article pre{background:#f5f5f5;padding:1rem;border-radius:6px;overflow-x:auto;font-size:.9rem}
article code{background:#f0f0f0;padding:.15rem .35rem;border-radius:3px;font-size:.9em}
article pre code{background:none;padding:0}
article a{color:#4a90d9;text-decoration:none}
article a:hover{text-decoration:underline}
article ul,article ol{padding-left:1.5rem}
article li{margin:.3rem 0}
article hr{border:none;border-top:1px solid #e0e0e0;margin:2rem 0}
footer{margin-top:3rem;padding-top:1.5rem;border-top:1px solid #e0e0e0;text-align:center;color:#999;font-size:.85rem}
footer a{color:#999}
@media(max-width:600px){.wrap{padding:1rem}h1{font-size:1.4rem}}