:root{--ink:#111;--muted:#555;--line:#ccc;--paper:#fafafa;--max:1080px}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:Georgia,"Songti SC","SimSun",serif;color:var(--ink);background:var(--paper);line-height:1.7}
a{color:inherit}
img{display:block;max-width:100%}
.container{width:min(var(--max),calc(100% - 40px));margin:0 auto}
.site-header{border-bottom:1px solid var(--ink);padding:14px 0;position:sticky;top:0;background:var(--paper);z-index:80}
.topbar{display:flex;justify-content:space-between;align-items:baseline;gap:16px;flex-wrap:wrap}
.brand{font-weight:700;letter-spacing:.08em;font-size:13px;text-transform:uppercase;text-decoration:none}
.nav{display:flex;gap:18px;font-size:13px}
.nav a{text-decoration:none}
.btn{display:inline-block;font-size:14px;padding:6px 0;border-bottom:1px solid var(--ink);text-decoration:none;font-family:inherit}
section{padding:48px 0;scroll-margin-top:56px}
.kicker{font-size:11px;letter-spacing:.18em;text-transform:uppercase;margin-bottom:8px}
.footer{border-top:1px solid var(--ink);padding:40px 0 20px;font-size:14px}
.footer-grid{display:grid;grid-template-columns:1.4fr .8fr .9fr;gap:24px}
.footer h3,.footer h4{font-size:13px;letter-spacing:.12em;text-transform:uppercase;margin-bottom:10px}
.footer ul{list-style:none}
.footer li{margin:6px 0}
.copyright{margin-top:24px;padding-top:12px;border-top:1px solid var(--line);font-size:12px;color:var(--muted)}
.fig{margin:20px 0;max-width:280px}
.fig img{width:100%;height:auto;filter:grayscale(1)}
.fig figcaption{font-size:12px;color:var(--muted);margin-top:6px;font-family:-apple-system,BlinkMacSystemFont,"Microsoft YaHei",sans-serif}
@media(max-width:720px){.nav{display:none}.footer-grid{grid-template-columns:1fr}}
img[data-src]{min-height:80px;background:rgba(128,128,128,.06)}
.below-fold{content-visibility:auto;contain-intrinsic-size:auto 400px}