:root{--bg:#F4F7FA;--white:#fff;--pale:#EAF1F6;--mint:#E9F8F8;--navy:#102E46;--dark:#163C57;--aqua:#13B8C5;--blue:#237BD3;--title:#18364B;--body:#344C60;--muted:#64798A;--line:#DCE6ED;--footer:#0B2539;--radius:14px}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);color:var(--body);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-x:hidden}body.drawer-active{overflow:hidden}a{color:#1766ac;text-decoration:none}a:hover{text-decoration:underline}img{max-width:100%;height:auto}p{margin:0 0 1.15em}h1,h2,h3{color:var(--title);line-height:1.35;margin:0 0 .75em;font-weight:750}h1{font-size:36px;letter-spacing:-.035em}h2{font-size:26px}h3{font-size:20px}ul,ol{padding-left:1.5em}li{margin:.35em 0}.container{width:min(100% - 56px,1200px);margin-inline:auto}.section{margin-block:58px}.narrow{max-width:790px}.eyebrow{font-size:13px;letter-spacing:.12em;text-transform:uppercase;font-weight:700;color:#117d90;margin-bottom:12px}.lead{font-size:17px;color:#486176;max-width:850px}.site-header{background:var(--white);border-bottom:1px solid var(--line)}.brand-bar{height:72px;display:flex;align-items:center;gap:24px}.brand{display:flex;align-items:center;min-width:0;flex:0 1 auto}.brand img{display:block;width:auto;max-width:min(230px,100%);max-height:38px;object-fit:contain}.brand-text{font-weight:800;font-size:22px;color:var(--navy);white-space:nowrap;line-height:1.1}.brand-text small,.footer-brand small{display:block;font-size:9px;letter-spacing:.12em}.brand-caption{font-size:13px;color:var(--muted);white-space:nowrap}.register-link{margin-left:auto;background:var(--navy);color:#fff;border-radius:8px;padding:7px 21px;font-size:14px;font-weight:700;white-space:nowrap}.register-link:hover{background:var(--dark);color:#fff;text-decoration:none}.desktop-nav{background:var(--navy)}.nav-inner{display:flex;align-items:stretch;justify-content:space-between;gap:4px;min-height:50px}.nav-inner a{display:flex;justify-content:center;align-items:center;position:relative;padding:8px 12px;color:#edf6fb;font-size:15px;font-weight:500;white-space:nowrap}.nav-inner a[aria-current="page"]{font-weight:800;color:#fff}.nav-inner a[aria-current="page"]:after{content:'';position:absolute;bottom:5px;left:25%;right:25%;height:3px;background:var(--aqua);border-radius:3px}.nav-inner a:hover{color:#fff;text-decoration:none;background:#1b4c68}.menu-button{display:none}.noscript-nav{display:flex;flex-wrap:wrap;gap:10px;padding-top:10px;padding-bottom:10px}.noscript-nav a{padding:5px 9px;background:#eaf1f6;border-radius:6px}.skip-link{position:absolute;z-index:50;top:-100px;left:20px;background:#fff;padding:8px}.skip-link:focus{top:8px}.drawer-shade,.mobile-drawer{visibility:hidden;pointer-events:none}.page-head{padding:52px 0 22px}.page-head .lead{max-width:825px}.breadcrumbs{font-size:13px;color:var(--muted);margin-bottom:14px}.breadcrumbs a{color:var(--muted)}.page-content{padding-bottom:24px}.article-section{margin:44px 0}.article-section p{max-width:790px}.article-section h2{border-bottom:1px solid var(--line);padding-bottom:14px}.article-section h3{margin-top:24px}.hero{display:grid;grid-template-columns:minmax(0,52fr) minmax(0,48fr);gap:36px;align-items:center;padding:52px 0 24px}.hero h1{font-size:42px}.hero p{max-width:660px}.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:8px 22px;border-radius:9px;background:var(--navy);color:#fff;font-weight:700}.button.alt{background:#d8f2f5;color:var(--navy)}.button:hover{text-decoration:none;filter:brightness(1.08)}.media-frame{display:flex;align-items:center;justify-content:center;min-width:0;max-width:100%;padding:10px;margin:0;border-radius:14px;background:var(--pale);overflow:hidden}.media-frame img{display:block;width:auto;height:auto;max-width:100%;max-height:var(--media-limit,220px);object-fit:contain;object-position:center}.media-frame--hero{--media-limit:310px}.media-frame--feature{--media-limit:250px}.media-frame--card{--media-limit:185px}.media-frame--mobile{--media-limit:350px;max-width:320px}.media-frame--banner{--media-limit:210px}.media-placeholder{min-height:145px;width:100%;display:grid;place-items:center;border:1px dashed #a7c4d5;color:#678696;border-radius:8px;font-size:13px}.media-frame--mobile .media-placeholder{min-height:230px}.two-cols,.feature-row{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:32px;align-items:center}.feature-row.reverse{direction:rtl}.feature-row.reverse>*{direction:ltr}.topic-index{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:42px}.topic-entry{border-top:1px solid var(--line);padding:20px 0}.topic-entry a{font-size:19px;font-weight:750;color:var(--title)}.topic-entry p{font-size:15px;margin:6px 0 0}.focus-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:26px}.focus-primary{background:var(--navy);color:#e6f0f6;padding:32px;border-radius:14px}.focus-primary h3{font-size:25px;color:#fff}.focus-primary a{color:#8ee6ed}.focus-aside{display:grid;gap:20px}.focus-aside article{padding:23px;background:var(--white);border:1px solid var(--line);border-radius:12px}.focus-aside h3{font-size:19px}.rule-pieces{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.rule-piece{border-left:4px solid var(--aqua);background:var(--white);padding:23px 24px;border-radius:0 12px 12px 0}.rule-piece:nth-child(2){margin-top:22px}.rule-piece:nth-child(3){margin-top:44px}.reading-path{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.path-step{background:#e7f0f5;border-radius:12px;padding:20px;border-top:3px solid var(--aqua)}.path-step b{display:block;color:var(--blue);font-size:14px}.path-step a{font-weight:700;color:var(--title)}.editor-note{border-left:4px solid var(--aqua);padding:20px 26px;background:var(--mint)}.topic-links{display:flex;gap:8px;flex-wrap:wrap;margin:20px 0 25px}.topic-links a{background:#e2eef5;padding:7px 14px;color:var(--navy);font-weight:650;border-radius:30px;font-size:14px}.topic-links a:hover{text-decoration:none;background:#cce6ef}.content-aside{display:grid;grid-template-columns:minmax(0,2.5fr) minmax(230px,1fr);align-items:start;gap:45px}.fact-panel{background:var(--white);padding:20px;border:1px solid var(--line);border-radius:12px}.fact-panel h3{font-size:18px}.fact-panel ul{font-size:14px;padding-left:18px}.table-scroll{width:100%;overflow-x:auto;background:var(--white);border-radius:12px;border:1px solid var(--line);margin:22px 0}.data-table{width:100%;border-collapse:collapse;min-width:610px;font-size:15px}.data-table caption{text-align:left;padding:15px 18px;font-weight:bold;color:var(--title)}.data-table th,.data-table td{text-align:left;vertical-align:top;padding:14px 16px;border-bottom:1px solid var(--line)}.data-table th{color:var(--navy);background:#eaf3f7}.data-table tr:last-child td{border-bottom:0}.flow-list{counter-reset:step;list-style:none;padding:0;display:grid;gap:16px}.flow-list li{counter-increment:step;background:var(--white);border:1px solid var(--line);padding:18px 22px 18px 65px;position:relative;border-radius:12px}.flow-list li:before{content:counter(step);position:absolute;top:17px;left:19px;width:30px;height:30px;background:var(--navy);color:#fff;border-radius:50%;display:grid;place-items:center;font-weight:700}.flow-list strong{display:block;color:var(--title)}.note{background:var(--mint);padding:22px 25px;border-radius:12px}.exhibit{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:center;gap:28px;margin:34px 0}.exhibit:nth-child(even){grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr)}.exhibit:nth-child(even) .media-frame{order:2}.quote{border-left:4px solid var(--aqua);font-size:20px;color:var(--navy);padding:12px 24px;margin:30px 0;background:#eaf6f7}.related{border-top:1px solid var(--line);padding-top:28px}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.related-item{display:flex;flex-direction:column;background:#fff;padding:20px;border:1px solid var(--line);border-radius:12px}.related-item strong{color:var(--title);font-size:17px}.related-item span{font-size:14px;color:var(--muted)}.faq-list{display:grid;gap:10px}.faq-list details{background:#fff;border:1px solid var(--line);border-radius:10px;padding:0 20px}.faq-list summary{cursor:pointer;font-weight:700;color:var(--title);padding:15px 0}.faq-list details[open] summary{border-bottom:1px solid var(--line)}.faq-list details p{padding-top:12px}.about-layout{display:grid;grid-template-columns:235px minmax(0,1fr);gap:44px;align-items:start}.about-sidebar{background:#fff;padding:20px;border-radius:12px;border:1px solid var(--line);position:sticky;top:15px}.about-sidebar a{display:block;padding:7px 0}.about-main .article-section:first-child{margin-top:0}.site-footer{background:var(--footer);color:#dcecf5;margin-top:60px;padding:42px 0 18px;font-size:14px}.footer-layout{display:grid;grid-template-columns:2fr 1fr;gap:45px}.footer-brand{color:#fff;font-weight:800;font-size:22px}.footer-brand small{font-size:10px}.footer-layout p{margin-top:14px}.footer-note{max-width:740px;font-size:13px;color:#bfd0db}.footer-layout nav{display:grid;grid-template-columns:1fr 1fr;align-content:start;gap:10px}.footer-layout nav a{color:#deeff5}.footer-bottom{border-top:1px solid #315268;padding-top:13px;margin-top:26px;color:#aac0cf}.mobile-shortcuts{display:none}.back-top{position:fixed;right:20px;bottom:24px;border:0;border-radius:50%;width:44px;height:44px;background:var(--navy);color:#fff;font-size:21px;cursor:pointer;box-shadow:0 3px 12px #0b253940}.back-top[hidden]{display:none}:focus-visible{outline:3px solid var(--aqua);outline-offset:3px}@media(max-width:1200px){.container{width:min(100% - 44px,1200px)}}@media(max-width:920px){.brand-bar{height:62px;justify-content:space-between;gap:8px}.brand img{max-height:30px;max-width:190px}.brand-caption,.desktop-nav{display:none}.menu-button{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:5px;background:transparent;border:1px solid var(--line);border-radius:8px;width:40px;height:40px;flex:none;cursor:pointer}.menu-button span{width:18px;height:2px;background:var(--navy)}.brand{margin-inline:auto}.register-link{margin:0;padding:7px 11px;font-size:12px;height:40px;display:flex;align-items:center}.noscript-nav{display:flex;flex-wrap:wrap;gap:10px;padding-top:10px;padding-bottom:10px}.noscript-nav a{padding:5px 9px;background:#eaf1f6;border-radius:6px}.drawer-shade{position:fixed;inset:0;background:#102e4685;z-index:40;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer-shade.is-open{opacity:1;visibility:visible;pointer-events:auto}.mobile-drawer{position:fixed;z-index:41;inset:0 auto 0 0;width:min(86vw,340px);background:#fff;transform:translateX(-102%);visibility:hidden;pointer-events:none;transition:transform .2s,visibility .2s;overflow-y:auto;box-shadow:4px 0 20px #102e4621}.mobile-drawer.is-open{visibility:visible;pointer-events:auto;transform:translateX(0)}.drawer-head{display:flex;align-items:center;justify-content:space-between;background:var(--navy);color:#fff;padding:13px 20px}.drawer-head button{background:transparent;border:0;color:#fff;font-size:28px;min-width:40px;min-height:40px;cursor:pointer}.mobile-drawer nav{padding:12px 25px 40px}.mobile-drawer nav p{margin:19px 0 6px;font-size:12px;font-weight:700;letter-spacing:.12em;color:#71899c}.mobile-drawer nav a{display:block;padding:10px 0;color:var(--navy);border-bottom:1px solid var(--line);font-weight:650}.mobile-shortcuts{display:flex;justify-content:space-around;gap:8px;flex-wrap:wrap;margin-top:32px;padding-top:15px;border-top:1px solid var(--line);font-size:14px}.mobile-shortcuts a{color:var(--navy)}.content-aside{grid-template-columns:minmax(0,1fr) 240px;gap:24px}body:not(.drawer-active) .mobile-drawer{pointer-events:none}}@media(max-width:760px){.hero,.two-cols,.feature-row,.focus-grid,.exhibit,.content-aside,.about-layout{grid-template-columns:1fr}.hero{gap:22px}.feature-row.reverse{direction:ltr}.exhibit:nth-child(even){grid-template-columns:1fr}.exhibit:nth-child(even) .media-frame{order:0}.rule-pieces,.reading-path,.related-grid{grid-template-columns:1fr 1fr}.rule-piece:nth-child(n){margin-top:0}.fact-panel{order:2}.about-sidebar{position:static;order:2}.footer-layout{grid-template-columns:1fr}.focus-aside{grid-template-columns:1fr 1fr}.section{margin-block:42px}}@media(max-width:640px){body{font-size:15px}.container{width:calc(100% - 32px)}h1{font-size:27px}h2{font-size:21px}h3{font-size:18px}.hero{padding-top:32px}.hero h1{font-size:30px}.page-head{padding:34px 0 12px}.lead{font-size:15px}.section{margin-block:34px}.topic-index,.focus-aside,.rule-pieces,.reading-path,.related-grid{grid-template-columns:1fr}.topic-entry{padding:16px 0}.focus-primary{padding:22px}.focus-aside{gap:12px}.focus-aside article{padding:18px}.media-frame--hero{--media-limit:205px}.media-frame--feature{--media-limit:185px}.media-frame--card{--media-limit:145px}.media-frame--mobile{--media-limit:285px;max-width:250px}.media-frame--banner{--media-limit:135px}.media-placeholder{min-height:110px}.rule-piece{padding:18px}.footer-layout nav{grid-template-columns:1fr 1fr}.article-section{margin:34px 0}.article-section h2{padding-bottom:10px}.brand img{max-width:142px}.brand-text{font-size:17px}.register-link{padding:5px 8px}.table-scroll{margin:16px 0}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}