@charset "UTF-8";
:root { color-scheme: light; --ink:#151719; --muted:#666a6e; --line:#e7e7e4; --accent:#2857db; }
* { box-sizing:border-box; }
html { scroll-behavior:smooth; }
body { margin:0; background:#fff; color:var(--ink); font:16px/1.65 "Segoe UI",Arial,"PingFang SC","Microsoft YaHei",sans-serif; -webkit-font-smoothing:antialiased; }
a { color:inherit; text-decoration:none; }
a:hover { color:var(--accent); }
a:focus-visible,summary:focus-visible,button:focus-visible { outline:2px solid var(--accent); outline-offset:5px; }
.wrap { width:min(1160px,calc(100% - 96px)); margin-inline:auto; }
.site-header { min-height:88px; display:flex; align-items:center; justify-content:space-between; gap:24px; border-bottom:1px solid var(--line); }
.wordmark { font-size:17px; letter-spacing:-.6px; font-weight:700; }
.wordmark span { font-weight:400; }
.site-header nav { display:flex; align-items:center; gap:24px; font-size:14px; }
.site-header nav [aria-hidden] { margin-left:4px; color:var(--muted); }
.language-switch { display:flex; align-items:center; gap:8px; border-left:1px solid var(--line); padding-left:20px; }
.language-switch button { border:0; background:none; color:var(--muted); font:inherit; font-size:12px; padding:4px 0; cursor:pointer; }
.language-switch button[aria-pressed="true"] { color:var(--ink); text-decoration:underline; text-underline-offset:5px; }
.language-switch button:disabled { cursor:default; opacity:.5; }
.hero { padding-top:78px; text-align:center; }
.eyebrow { margin:0 0 18px; font-size:12px; letter-spacing:.08em; text-transform:uppercase; font-weight:600; color:var(--muted); }
h1 { margin:0; font-size:clamp(44px,6.6vw,88px); line-height:1.05; font-weight:650; letter-spacing:-.065em; }
h1 span { font-weight:350; }
.hero-description { max-width:650px; margin:25px auto 28px; font-size:20px; line-height:1.5; color:var(--muted); letter-spacing:-.25px; }
.paper-button { display:inline-flex; align-items:center; gap:36px; border-radius:100px; background:var(--ink); color:white; padding:12px 24px; font-size:14px; }
.paper-button:hover { color:white; background:var(--accent); }
.study-numbers { display:grid; grid-template-columns:repeat(5,max-content); justify-content:center; column-gap:48px; row-gap:24px; margin:44px 0 0; }
.study-numbers div { min-width:80px; }
.study-numbers dd { margin:0; font-size:29px; line-height:1.2; font-weight:500; letter-spacing:-1px; }
.study-numbers dt { margin-top:6px; font-size:12px; color:var(--muted); }
.paper-figure { margin:0; min-width:0; }
.paper-art { display:block; width:100%; height:auto; border:0; background:white; }
.hero-figure { margin-top:50px; padding:0 12px; }
.lead-results { display:grid; grid-template-columns:1fr 1fr; column-gap:110px; margin-top:44px; text-align:left; }
.lead-results .chapter-copy { padding-top:0; }
figcaption { display:flex; justify-content:space-between; gap:20px; text-align:left; font-size:17px; line-height:1.65; color:var(--muted); margin-top:15px; }
figcaption a { flex:none; color:var(--ink); }
.chapter { display:grid; grid-template-columns:1fr 1fr; column-gap:110px; row-gap:46px; padding-top:92px; margin-top:72px; border-top:1px solid var(--line); scroll-margin-top:32px; }
h2 { font-size:clamp(28px,3vw,40px); letter-spacing:-1.5px; line-height:1.2; font-weight:550; margin:0; }
.chapter-heading .eyebrow { margin-bottom:20px; }
.chapter-copy { padding-top:35px; max-width:490px; font-size:17px; letter-spacing:-.2px; }
.chapter-copy p { margin:0 0 16px; }
.quiet { color:var(--muted); }
.full-width { grid-column:1/-1; }
.overview-figure { max-width:1100px; width:100%; justify-self:center; }
.benchmark-figure { max-width:1000px; width:100%; justify-self:center; }
.results-figure { max-width:1160px; width:100%; margin-inline:auto; padding:0; justify-self:center; }
.all-results { border-top:1px solid var(--line); border-bottom:1px solid var(--line); margin-top:10px; }
summary { display:flex; align-items:center; justify-content:space-between; cursor:pointer; list-style:none; padding:21px 0; font-size:15px; }
summary::-webkit-details-marker { display:none; }
summary .disclosure-icon { font-size:24px; line-height:1; font-weight:300; transition:transform .2s; }
details[open] summary .disclosure-icon { transform:rotate(45deg); }
.paper-resources { padding:0 0 18px; }
.paper-resources p { margin:10px 0; font-size:14px; color:var(--muted); }
.paper-resources a:hover { color:var(--accent); }
.dataset { display:grid; grid-template-columns:1fr 1fr; gap:110px; margin-top:112px; padding-top:54px; padding-bottom:70px; border-top:1px solid var(--line); }
.dataset-copy { color:var(--muted); }
.dataset-copy p { margin:0 0 20px; }
.text-link { font-size:14px; color:var(--ink); border-bottom:1px solid var(--ink); padding-bottom:4px; }
footer { display:flex; justify-content:space-between; border-top:1px solid var(--line); padding:25px 0 30px; font-size:12px; color:var(--muted); }
.skip-link { position:absolute; left:20px; top:-60px; background:var(--ink); color:white; padding:8px 16px; z-index:2; }
.skip-link:focus { top:10px; }
:lang(zh-CN) h2 { letter-spacing:0; line-height:1.35; }
:lang(zh-CN) .eyebrow { letter-spacing:.04em; text-transform:none; }
:lang(zh-CN) .chapter-copy,:lang(zh-CN) figcaption { line-height:1.9; letter-spacing:0; }
@media (max-width:900px) { .wrap { width:calc(100% - 48px); } .hero { padding-top:55px; } h1 { font-size:clamp(44px,8.5vw,74px); } .chapter,.dataset { column-gap:48px; } .chapter-copy,figcaption { font-size:16px; } .study-numbers { gap:38px; } .chapter { padding-top:58px; margin-top:55px; } }
@media (max-width:620px) { .wrap { width:calc(100% - 36px); } .site-header { min-height:72px; gap:12px; } .wordmark { font-size:14px; letter-spacing:-.5px; } .site-header nav { gap:16px; font-size:12px; } .hero { padding-top:45px; } h1 { font-size:clamp(36px,8.3vw,50px); letter-spacing:-.06em; } .hero-description { font-size:17px; max-width:360px; margin-top:20px; } .eyebrow { font-size:10px; } .study-numbers { gap:12px; justify-content:space-between; margin-top:36px; } .study-numbers div { min-width:0; } .study-numbers dd { font-size:25px; } .study-numbers dt { font-size:10px; } .hero-figure { padding:0; margin-top:35px; } figcaption { font-size:16px; gap:12px; } .chapter { grid-template-columns:1fr; row-gap:26px; padding-top:42px; margin-top:46px; } h2 { font-size:30px; letter-spacing:-1px; } .chapter-heading .eyebrow { margin-bottom:12px; } .chapter-copy { padding-top:0; max-width:none; } .chapter-copy p { margin-bottom:12px; } .dataset { grid-template-columns:1fr; gap:22px; margin-top:64px; padding-top:38px; padding-bottom:44px; } .dataset-copy { font-size:15px; } .paper-resources p { font-size:12px; } }
@media (max-width:620px) { .site-header { flex-wrap:wrap; row-gap:10px; padding:18px 0; } .site-header nav { margin-left:auto; gap:14px; } .language-switch { padding-left:12px; gap:8px; } }
@media (max-width:620px) { .study-numbers { grid-template-columns:repeat(2,minmax(0,1fr)); row-gap:22px; } .study-numbers .token-metric { grid-column:1/-1; } }
@media (max-width:900px) { .lead-results { column-gap:48px; } }
@media (max-width:620px) { .lead-results { grid-template-columns:1fr; gap:22px; margin-top:32px; } }
@media (prefers-reduced-motion:reduce) { html { scroll-behavior:auto; } summary .disclosure-icon { transition:none; } }