:root{--fg:#1a1a1a;--muted:#666;--link:#1155cc;--bg:#fff;--line:#e5e5e5}
*{box-sizing:border-box}
body{margin:0;font:16px/1.6 -apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;color:var(--fg);background:var(--bg)}
.site-header{border-bottom:1px solid var(--line);padding:14px 20px}
.brand{font-weight:700;font-size:20px;color:var(--fg);text-decoration:none}
.content{max-width:820px;margin:0 auto;padding:28px 20px 60px}
.content h1{font-size:28px;line-height:1.25;margin:0 0 18px}
.content a{color:var(--link)}
.content img{max-width:100%;height:auto}
.content table{border-collapse:collapse;max-width:100%}
.content td,.content th{border:1px solid var(--line);padding:6px 10px}
.content iframe{max-width:100%}
.index-list{columns:2;gap:28px;padding-left:18px}
.index-list li{margin:2px 0;break-inside:avoid}
.site-footer{border-top:1px solid var(--line);color:var(--muted);padding:20px;text-align:center;font-size:14px}
@media(max-width:640px){.index-list{columns:1}}