:root{color-scheme:light;--paper:#faf8f3;--ink:#292620;--muted:#716c62;--line:#e3ddd1;--accent:#8b4a13;--highlight:#f1e4ce;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;font-synthesis:none}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font-size:16px;line-height:1.75;-webkit-font-smoothing:antialiased}
html{scroll-padding-top:24px}
html[data-current-language="en"] [data-language="zh"],html[data-current-language="zh"] [data-language="en"]{display:none}
a{color:var(--accent);text-underline-offset:.22em;text-decoration-thickness:1px;overflow-wrap:anywhere}
a:hover{text-decoration-thickness:2px}
button,a{-webkit-tap-highlight-color:transparent}
:focus-visible{outline:3px solid var(--accent);outline-offset:5px;border-radius:3px}
.site-shell{max-width:960px;margin:auto;padding:0 40px}
header{display:flex;align-items:center;gap:30px;min-height:104px;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-size:20px;font-weight:650;letter-spacing:-.6px;text-decoration:none;margin-right:auto}
.brand small{display:block;font-size:11px;color:var(--muted);font-weight:400;letter-spacing:2px;line-height:1.4}
.brand-mark{font-size:38px;line-height:1;color:var(--accent);font-weight:400}
nav{display:flex;gap:24px}
nav a{color:var(--muted);text-decoration:none;font-size:14px;padding:10px 0}
nav a[aria-current="page"]{color:var(--ink);text-decoration:underline;text-decoration-color:var(--accent);text-underline-offset:9px}
.languages{display:flex;border:1px solid var(--line);border-radius:7px;padding:3px;gap:2px}
.languages button{font:inherit;font-size:12px;line-height:1.4;min-width:44px;min-height:38px;border:0;border-radius:4px;background:transparent;color:var(--muted);cursor:pointer}
.languages button[aria-pressed="true"]{background:var(--highlight);color:var(--accent);font-weight:600}
.intro{padding:70px 0 48px;max-width:700px}
.eyebrow{font-size:11px;letter-spacing:2.4px;color:var(--accent);font-weight:600;margin:0 0 16px}
h1{font-size:clamp(38px,6vw,58px);font-weight:600;line-height:1.2;letter-spacing:-1.8px;margin:0 0 22px}
.lede{font-size:19px;line-height:1.65;color:var(--muted);margin:0 0 20px;max-width:620px}
.updated{font-size:12px;color:var(--muted);margin:0}
.section{border-top:1px solid var(--line);padding:30px 0 34px;display:grid;grid-template-columns:55px minmax(0,1fr);gap:22px}
.section-number{font-size:12px;letter-spacing:1px;color:var(--accent);padding-top:6px;font-variant-numeric:tabular-nums}
h2{font-size:23px;line-height:1.4;font-weight:600;letter-spacing:-.35px;margin:0 0 16px}
h3{font-size:16px;line-height:1.5;margin:25px 0 8px;font-weight:650}
.prose p{margin:0 0 14px}
.prose p:last-child{margin-bottom:0}
.prose ul,.prose ol{padding-left:22px;margin:0}
.prose li{margin-bottom:12px;padding-left:3px}
.prose li:last-child{margin-bottom:0}
.email{font-weight:600}
footer{display:flex;flex-wrap:wrap;gap:12px 24px;align-items:center;border-top:1px solid var(--line);padding:28px 0 38px;font-size:12px;color:var(--muted)}
footer p{margin:0 auto 0 0}
footer a{color:var(--muted)}
.skip{position:absolute;top:8px;left:8px;transform:translateY(-180%);padding:8px 16px;background:var(--paper);z-index:10}
.skip:focus{transform:translateY(0)}
@media(max-width:600px){.site-shell{padding:0 22px}header{gap:14px;flex-wrap:wrap;padding:20px 0;min-height:0}.brand{font-size:19px}nav{gap:18px;order:3;width:100%}.intro{padding:42px 0 32px}.lede{font-size:17px}.section{grid-template-columns:26px minmax(0,1fr);gap:12px;padding:26px 0}h2{font-size:21px}body{font-size:15px}footer{padding:22px 0 30px}footer p{width:100%}}
@media print{body{background:white;color:black}.site-shell{max-width:none;padding:0}header{min-height:70px}nav,.languages,.skip{display:none}.intro{padding:30px 0}.section{break-inside:avoid}a{color:inherit}footer{padding-bottom:0}}