@charset "UTF-8";
:root{--ink:#182c42;--muted:#63758a;--line:#dce4eb;--paper:#fff;--canvas:#f4f7fa;--blue:#174dff;--navy:#0c2137;--mint:#b4f6da;--orange:#f97948;--serif:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;--sans:"Microsoft YaHei UI","PingFang SC","Noto Sans CJK SC",system-ui,sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;color:var(--ink);background:var(--paper);font-family:var(--sans);font-size:16px;line-height:1.75;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible{outline:3px solid var(--blue);outline-offset:5px}::selection{background:var(--mint);color:var(--navy)}.wrap{width:min(1240px,calc(100% - 112px));margin:auto}.skip-link{position:fixed;left:16px;top:-100px;z-index:30;background:white;padding:12px;border:2px solid var(--blue)}.skip-link:focus{top:16px}.masthead{border-bottom:1px solid var(--line)}.topline{height:98px;display:flex;align-items:center;justify-content:space-between;gap:28px}.brand{display:flex;align-items:center;gap:13px;white-space:nowrap}.brand-mark{display:grid;place-items:center;width:37px;height:37px;background:var(--blue);color:white;font-family:var(--serif);font-size:24px;line-height:1}.brand-word{font-weight:700;letter-spacing:.08em;font-size:21px}.brand-small{display:block;font-family:monospace;font-size:10px;letter-spacing:.24em;color:var(--muted);line-height:1.7;margin-top:1px}.nav{display:flex;gap:35px;align-items:center;font-size:15px}.nav a{position:relative;padding:8px 0}.nav a:hover,.nav [aria-current=page]{color:var(--blue)}.nav [aria-current=page]:after{content:"";position:absolute;bottom:-29px;left:0;right:0;height:3px;background:var(--blue)}.site-domain{font-family:monospace;font-size:12px;color:var(--muted);border-left:1px solid var(--line);padding-left:30px}.eyebrow{font-family:monospace;font-size:12px;font-weight:500;letter-spacing:.16em;text-transform:uppercase;display:flex;align-items:center;gap:12px;color:var(--muted)}.eyebrow:before{content:"";width:23px;height:2px;background:var(--blue)}.intro{padding:47px 0 36px;display:grid;grid-template-columns:1.25fr 1fr;align-items:end;gap:70px}.intro h1{font-family:var(--serif);font-size:clamp(34px,3.5vw,49px);font-weight:600;line-height:1.4;letter-spacing:.02em;margin:14px 0 0}.intro p{max-width:420px;color:var(--muted);font-size:16px;margin:0 0 3px;line-height:1.95}.feature{display:grid;grid-template-columns:1.05fr 1fr;background:var(--navy);color:white;min-height:328px;overflow:hidden}.feature-copy{padding:35px 40px 36px;display:flex;align-items:flex-start;flex-direction:column}.meta{display:flex;align-items:center;gap:14px;font-size:12px;letter-spacing:.06em;color:var(--muted);flex-wrap:wrap}.feature .meta{color:#c8d7e6}.tag{font-size:12px;letter-spacing:.1em;text-transform:uppercase}.feature .tag{color:var(--mint)}.meta-separator{height:12px;width:1px;background:currentColor;opacity:.45}.feature h2{font-family:var(--serif);font-size:clamp(26px,2.7vw,36px);font-weight:500;line-height:1.5;margin:18px 0 12px;max-width:470px;letter-spacing:.01em}.feature p{color:#b9c9d7;font-size:15px;margin:0;max-width:395px;line-height:1.9}.read-link{display:inline-flex;align-items:center;justify-content:center;margin-top:auto;padding-top:25px;font-size:14px;gap:16px}.read-link span{border-bottom:1px solid var(--mint);padding-bottom:3px}.read-link:hover span{color:var(--mint)}.feature-art{border-left:1px solid #263b50;position:relative;background:linear-gradient(0deg,transparent 39px,#ffffff05 40px),linear-gradient(90deg,transparent 39px,#ffffff05 40px);background-size:40px 40px;display:flex;flex-direction:column;justify-content:center;padding:33px 37px 30px}.diagram-label{display:flex;justify-content:space-between;gap:15px;font-family:monospace;color:#8da7bd;font-size:11px;letter-spacing:.12em;margin-bottom:20px}.flow{display:flex;align-items:center;gap:0}.flow-node{border:1px solid #56728a;padding:15px 12px;flex:1;min-width:0;text-align:center;background:#152d43}.flow-node strong{display:block;font-size:15px;font-weight:500;white-space:nowrap}.flow-node small{display:block;color:#9cb4c8;font-family:monospace;font-size:11px;letter-spacing:.1em;margin-top:7px}.flow-node:first-child{border-color:var(--mint)}.flow-node:first-child small{color:var(--mint)}.flow-line{width:35px;flex:none;height:1px;background:#749e9c;position:relative}.flow-line:after{content:"";width:4px;height:4px;position:absolute;right:0;top:-2px;background:var(--mint);border-radius:50%}.protocol{font-family:monospace;font-size:11px;letter-spacing:.13em;color:var(--mint);margin:18px 0 23px;text-align:center}.diagram-note{display:flex;justify-content:space-between;gap:20px;border-top:1px solid #294153;padding-top:16px;font-size:12px;color:#91a9bc}.diagram-note span:last-child{color:var(--mint)}.section-head{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:39px 0 20px;border-bottom:1px solid var(--line);margin-bottom:0}.section-head h2{margin:0;font-size:21px;font-weight:600;letter-spacing:.04em}.section-head small{font-family:monospace;color:var(--muted);font-size:12px}.article-grid{display:grid;grid-template-columns:repeat(3,1fr);border-bottom:1px solid var(--line)}.article-card{padding:28px 28px 25px 0;display:flex;flex-direction:column;min-height:262px;position:relative}.article-card:not(:nth-child(3n+1)){padding-left:28px;border-left:1px solid var(--line)}.article-card:nth-child(n+4){border-top:1px solid var(--line)}.article-card h3{font-family:var(--serif);font-weight:600;font-size:23px;line-height:1.6;margin:13px 0 9px;max-width:320px}.article-card p{font-size:14px;color:var(--muted);margin:0;line-height:1.85}.article-card .card-bottom{display:flex;justify-content:space-between;align-items:center;margin-top:auto;padding-top:23px;font-size:12px;color:var(--muted)}.card-category{font-size:12px;color:var(--blue);letter-spacing:.06em}.card-number{font-family:monospace;color:#94a2b2;font-size:12px}.article-card:hover h3{color:var(--blue)}.card-bottom .read-text{color:var(--ink);border-bottom:1px solid #c2ccd5;padding-bottom:1px}.topics-section{padding:50px 0 55px;display:grid;grid-template-columns:245px 1fr;gap:60px;align-items:start}.topics-section h2{font-family:var(--serif);font-size:26px;margin:7px 0 13px;font-weight:500}.topics-section p{font-size:14px;color:var(--muted);line-height:1.85;margin:0}.topic-list{display:grid;grid-template-columns:1fr 1fr;gap:0 36px}.topic-link{border-bottom:1px solid var(--line);display:flex;align-items:center;gap:15px;padding:13px 0;font-size:15px}.topic-link span{color:#8c9cad;font-family:monospace;font-size:12px}.topic-link:hover{color:var(--blue)}.about-strip{background:var(--canvas);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.about-strip-inner{padding:32px 0;display:flex;align-items:center;gap:32px;justify-content:space-between}.about-strip h2{font-family:var(--serif);font-size:23px;font-weight:500;margin:0 0 8px}.about-strip p{font-size:14px;color:var(--muted);margin:0;max-width:810px}.outline-link{white-space:nowrap;padding:9px 19px;border:1px solid #c4cfd8;font-size:14px}.outline-link:hover{border-color:var(--blue);color:var(--blue)}.footer-inner{padding:27px 0 29px;display:flex;justify-content:space-between;align-items:center;gap:25px;color:var(--muted);font-size:12px;flex-wrap:wrap}.footer-links{display:flex;gap:25px}.footer a:hover{color:var(--blue)}.article-top{padding:25px 0 23px;color:var(--muted);font-size:13px;border-bottom:1px solid var(--line)}.article-top a:hover{color:var(--blue)}.article-top span{margin:0 12px;color:#a4b0bb}.article-layout{display:grid;grid-template-columns:minmax(0,760px) 225px;gap:80px;justify-content:center;padding:47px 0 70px}.article-header .meta{margin-bottom:16px}.article-header h1{font-family:var(--serif);font-weight:600;font-size:clamp(29px,3.1vw,42px);line-height:1.55;margin:0 0 20px;letter-spacing:.025em}.article-lead{font-size:18px;color:var(--muted);line-height:1.95;margin:0 0 36px;padding-bottom:30px;border-bottom:1px solid var(--line)}.prose{font-size:17px;line-height:2.05}.prose h2{font-family:var(--serif);font-size:27px;font-weight:600;margin:39px 0 16px;line-height:1.6;scroll-margin-top:25px}.prose p{margin:0 0 20px}.prose pre{white-space:pre-wrap;overflow-wrap:anywhere;margin:25px 0 30px;background:var(--navy);color:#c5f1e3;border-left:3px solid var(--mint);padding:22px 25px;font-size:14px;line-height:1.9;font-family:Consolas,monospace}.article-aside{border-left:1px solid var(--line);padding-left:24px;align-self:start;position:sticky;top:32px;margin-top:5px}.aside-label{font-family:monospace;font-size:11px;letter-spacing:.14em;color:var(--muted);margin:0 0 15px}.toc{list-style:none;padding:0;margin:0}.toc li{margin:13px 0;font-size:13px;line-height:1.7}.toc a:hover{color:var(--blue)}.aside-note{border-top:1px solid var(--line);margin-top:28px;padding-top:20px;color:var(--muted);font-size:12px;line-height:1.9}.references{padding-top:25px;border-top:1px solid var(--line);margin-top:40px;font-size:14px}.references h2{font-size:18px;margin:0 0 12px}.references ul{padding-left:20px}.references a{color:var(--blue);text-decoration:underline;text-underline-offset:4px;overflow-wrap:anywhere}.references li{margin:9px 0}.article-pagination{display:flex;justify-content:space-between;gap:35px;padding:28px 0 0;border-top:1px solid var(--line);margin-top:36px;font-size:14px}.article-pagination a{max-width:47%}.article-pagination small{display:block;color:var(--muted);font-size:12px;margin-bottom:8px}.article-pagination a:hover{color:var(--blue)}.about-page{width:min(840px,100%);margin:0 auto;padding:52px 0 70px}.about-page h1{font-family:var(--serif);font-size:44px;font-weight:600;line-height:1.4;margin:15px 0 26px}.about-page .lead{font-size:21px;line-height:1.9;color:var(--muted);margin-bottom:36px}.about-section{border-top:1px solid var(--line);padding-top:25px;margin-top:30px}.about-section h2{font-family:var(--serif);font-size:26px;font-weight:600}.about-section p{font-size:16px;line-height:2}.about-section ul{padding-left:22px;line-height:2.1}.article-page .nav [aria-current=page]:after{display:none}.reading-progress{height:2px;background:var(--blue);position:fixed;top:0;left:0;width:0;z-index:10}.not-found{padding:80px 0 120px;max-width:660px}.not-found h1{font-family:var(--serif);font-size:40px}.not-found a{color:var(--blue);text-decoration:underline}
@media(min-width:1600px){.wrap{width:min(1360px,calc(100% - 160px))}.intro{padding-top:60px}.feature{min-height:355px}.feature-copy{padding:42px 48px}.article-card{min-height:260px}}
@media(max-width:1100px){.wrap{width:calc(100% - 64px)}.site-domain{display:none}.intro{gap:35px}.feature-copy{padding:30px}.feature-art{padding:30px 22px}.flow-line{width:18px}.flow-node{padding:14px 8px}.flow-node strong{font-size:13px}.article-layout{gap:40px;grid-template-columns:minmax(0,1fr) 190px}.topics-section{gap:35px;grid-template-columns:210px 1fr}}
@media(max-width:760px){.wrap{width:calc(100% - 40px)}.topline{height:83px;gap:15px}.brand-word{font-size:18px;letter-spacing:.04em}.brand-mark{width:31px;height:34px;font-size:22px}.brand-small{font-size:9px;letter-spacing:.18em}.brand{gap:9px}.nav{gap:18px;font-size:14px}.nav [aria-current=page]:after{bottom:-21px}.intro{grid-template-columns:1fr;gap:21px;padding:32px 0 27px}.intro h1{font-size:35px}.intro p{font-size:15px;max-width:530px}.eyebrow{font-size:11px}.feature{grid-template-columns:1fr}.feature-copy{padding:28px 28px 30px}.feature h2{font-size:28px;max-width:400px}.feature p{max-width:500px}.feature-art{border-top:1px solid #263b50;border-left:0;padding:24px 28px}.diagram-label{margin-bottom:15px}.protocol{margin:13px 0 17px}.flow-node{padding:13px 10px}.flow-node strong{font-size:14px}.flow-line{width:25px}.read-link{padding-top:23px}.section-head{padding-top:30px}.article-grid{grid-template-columns:1fr 1fr}.article-card{padding:23px 20px 22px 0;min-height:255px}.article-card:not(:nth-child(3n+1)){padding-left:0;border-left:0}.article-card:nth-child(2n){border-left:1px solid var(--line);padding-left:20px;padding-right:0}.article-card:nth-child(n+3){border-top:1px solid var(--line)}.article-card h3{font-size:21px}.topics-section{grid-template-columns:1fr;gap:18px;padding:36px 0}.topics-section h2{margin-top:8px}.topics-section p{max-width:500px}.topic-list{gap:0 25px}.topic-link{font-size:14px}.about-strip-inner{align-items:flex-start;flex-direction:column;gap:18px;padding:27px 0}.footer-inner{gap:17px}.article-layout{grid-template-columns:1fr;gap:0;padding-top:30px}.article-aside{display:none}.article-header h1{font-size:32px}.article-lead{font-size:17px}.prose{font-size:17px}.prose h2{font-size:25px}.article-top{padding:18px 0}.about-page{padding-top:34px}.about-page h1{font-size:36px}.about-page .lead{font-size:19px}}
@media(max-width:420px){.wrap{width:calc(100% - 32px)}.brand-small{display:none}.brand-word{font-size:17px}.nav{gap:13px;font-size:13px}.topline{height:73px}.nav [aria-current=page]:after{bottom:-18px}.intro h1{font-size:32px}.feature-copy{padding:25px 23px}.feature h2{font-size:27px}.feature-art{padding:23px}.flow-node strong{font-size:12px}.flow-node small{font-size:10px}.flow-line{width:18px}.diagram-note{font-size:11px;gap:12px}.article-grid{grid-template-columns:1fr}.article-card,.article-card:nth-child(2n),.article-card:not(:nth-child(3n+1)){padding:22px 0;border-left:0;min-height:220px}.article-card:nth-child(n+2){border-top:1px solid var(--line)}.article-card h3{font-size:23px;max-width:none}.article-card p{font-size:15px}.topic-list{grid-template-columns:1fr}.section-head small{font-size:11px}.article-header h1{font-size:29px}.article-lead{font-size:16px}.article-pagination{gap:22px}.about-page h1{font-size:33px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}