:root{--bg:#f7f5f0;--card:#fff;--text:#1d2433;--muted:#5b6475;--accent:#2f5aa8;--line:#e3e0d8}
@media (prefers-color-scheme:dark){:root{--bg:#14171d;--card:#1d222b;--text:#eceff4;--muted:#a3abb9;--accent:#7fa6ee;--line:#2c323d}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang HK","Noto Sans HK","Microsoft JhengHei",sans-serif;-webkit-text-size-adjust:100%}
header,main,footer{max-width:760px;margin:0 auto;padding:0 20px}
header{padding-top:28px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px}
.brand{font-weight:700;font-size:20px;color:var(--text);text-decoration:none}
nav a{color:var(--accent);text-decoration:none;margin-left:16px;font-size:15px}
nav a:first-child{margin-left:0}
h1{font-size:30px;line-height:1.2;margin:28px 0 6px}
h2{font-size:21px;margin:34px 0 10px;padding-top:6px;border-top:1px solid var(--line)}
h3{font-size:17px;margin:20px 0 4px}
.sub{color:var(--muted);margin:0 0 20px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:18px 20px;margin:16px 0}
.en{color:var(--muted)}
p.en,li .en,div.en{font-size:15px}
a{color:var(--accent)}
ul{padding-left:22px}
table{width:100%;border-collapse:collapse;font-size:15px}
th,td{text-align:left;vertical-align:top;padding:8px 6px;border-bottom:1px solid var(--line)}
.lang-switch{font-size:14px;color:var(--muted)}
footer{color:var(--muted);font-size:14px;padding-top:30px;padding-bottom:40px}
details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 16px;margin:10px 0}
summary{cursor:pointer;font-weight:600}