:root{--bg:#F4F7FA;--paper:#fff;--pale:#EAF1F6;--cyan-pale:#E9F8F8;--nav:#102E46;--deep:#163C57;--cyan:#13B8C5;--blue:#237BD3;--ink:#18364B;--body:#344C60;--muted:#64798A;--line:#DCE6ED;--footer:#0B2539}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:28px}body{margin:0;background:var(--bg);color:var(--body);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}a{color:#176aa8;text-underline-offset:3px}a:hover{color:#0d526f}button{font:inherit}img{display:block;max-width:100%}.wrap{width:min(100% - 56px,1200px);margin-inline:auto}h1,h2,h3{color:var(--ink);line-height:1.38}h1{font-size:clamp(30px,3.3vw,40px);letter-spacing:-.025em}h2{font-size:clamp(23px,2.2vw,28px);margin:0 0 20px}h3{font-size:20px;margin:0 0 10px}p{margin:0 0 17px}p:last-child{margin-bottom:0}section{scroll-margin-top:26px}section.section{margin-block:60px}strong{color:var(--ink)}.skip-link{position:absolute;left:12px;top:-80px;z-index:99;padding:8px 12px;background:white}.skip-link:focus{top:10px}.site-header{background:#fff}.brandbar{height:72px;display:flex;align-items:center;gap:18px}.brand{display:flex;align-items:center;text-decoration:none;flex:0 0 auto;color:var(--nav)}.brand-text{font-weight:900;font-size:24px;letter-spacing:.04em}.brand-text em{font-style:normal;color:#058994}.brand-desc{font-size:13px;color:var(--muted);margin-right:auto}.brand .media-frame{padding:0;background:transparent;min-height:0;border:none}.media-frame--logo img{max-height:38px}.register-link{margin-left:auto;display:inline-flex;align-items:center;justify-content:center;background:var(--nav);color:white;border-radius:9px;padding:9px 19px;font-weight:700;text-decoration:none;white-space:nowrap}.register-link:hover{color:white;background:#205172}.desktop-nav{background:var(--nav)}.nav-inner{min-height:50px;display:flex;justify-content:space-between;gap:8px;align-items:stretch}.nav-inner a{color:#ecf5fa;font-size:15px;font-weight:600;text-decoration:none;display:flex;align-items:center;justify-content:center;padding:9px 12px;border-bottom:3px solid transparent;white-space:nowrap}.nav-inner a:hover,.nav-inner a[aria-current=page]{color:white;background:rgba(255,255,255,.08);border-bottom-color:var(--cyan)}.menu-toggle{display:none}.noscript-nav{display:none}.breadcrumb{padding-top:28px;color:var(--muted);font-size:14px}.breadcrumb a{color:var(--muted)}.page-intro{padding:16px 0 27px;max-width:900px}.page-intro h1{margin:0 0 18px;font-size:35px}.lead{font-size:18px;line-height:1.85}.eyebrow{font-size:12px;letter-spacing:.16em;color:#147d87;font-weight:800}.hero{display:grid;grid-template-columns:1.08fr 1fr;gap:36px;align-items:center;margin-block:40px 52px}.hero h1{font-size:42px;margin:10px 0 21px}.hero .lead{font-size:18px}.action-row{display:flex;gap:11px;flex-wrap:wrap;margin-top:24px}.button-link{background:var(--nav);color:#fff;text-decoration:none;padding:11px 20px;border-radius:10px;font-weight:700}.button-link.secondary{background:#e3f6f7;color:#135268}.button-link:hover{color:white;background:#205172}.button-link.secondary:hover{color:#123b4a;background:#c9eef0}.media-frame{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;margin:0;padding:9px;border-radius:14px;background:var(--pale)}.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--banner{--media-limit:210px}.media-frame--rules{--media-limit:220px}.media-frame--mobile{--media-limit:350px;max-width:320px;margin:auto}.media-frame--missing{min-height:100px;background:linear-gradient(135deg,#eaf1f6,#edf6f7);border:1px dashed #b6cbd5;color:var(--muted);font-size:13px}.media-frame--hero.media-frame--missing{min-height:190px}.media-frame--feature.media-frame--missing{min-height:140px}.feature-split{display:grid;grid-template-columns:1fr 1.1fr;gap:38px;align-items:center}.feature-split.reverse{grid-template-columns:1.2fr 1fr}.feature-split>*{min-width:0}.feature-split.reverse .media-frame{order:2}.topic-index{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:42px}.topic-item{padding:19px 0;border-top:1px solid var(--line);min-width:0}.topic-item h3{margin:0 0 8px}.topic-item a{font-weight:700}.focus-layout{display:grid;grid-template-columns:1.65fr 1fr;gap:24px}.focus-main{background:var(--nav);color:#e8f4f8;padding:30px;border-radius:14px}.focus-main h3,.focus-main strong{color:white}.focus-main a{color:#7fe5ef}.focus-side{display:grid;gap:16px}.note-block{padding:20px;background:#fff;border:1px solid var(--line);border-radius:12px}.note-block h3{font-size:19px}.ink-band{background:#e7f2f5;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:30px}.text-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.mini-lesson{border-top:3px solid var(--cyan);padding:20px 19px;background:#fff;min-width:0}.mini-lesson:nth-child(2){margin-top:20px}.mini-lesson:nth-child(3){margin-top:40px}.reading-path{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0;counter-reset:path}.path-step{padding:20px;border-left:1px solid var(--line);counter-increment:path}.path-step:before{content:'0' counter(path);display:block;color:#008c9b;font-weight:800;font-size:21px}.editorial-note{border-left:4px solid var(--cyan);padding:18px 22px;background:#e9f8f8}.section-nav{display:flex;gap:9px;flex-wrap:wrap;margin:18px 0 30px}.section-nav a{border:1px solid #c7dce5;border-radius:99px;padding:7px 15px;background:#fff;text-decoration:none;font-weight:700;font-size:14px}.article-layout{display:grid;grid-template-columns:minmax(0,760px) minmax(190px,1fr);gap:48px;align-items:start}.article-layout>*{min-width:0}.article{max-width:800px}.article>section{margin-bottom:44px}.article h2{margin-top:0}.article h3{margin-top:25px}.article p{line-height:1.85}.aside-index{background:white;border:1px solid var(--line);padding:20px;border-radius:12px;position:sticky;top:20px}.aside-index h3{font-size:17px}.aside-index a{display:block;padding:9px 0;border-bottom:1px solid var(--line);font-size:14px}.callout{padding:21px 24px;background:var(--cyan-pale);border-left:3px solid var(--cyan);margin:20px 0}.step-list{list-style:none;counter-reset:st;padding:0;margin:20px 0}.step-list li{counter-increment:st;position:relative;padding:15px 15px 15px 64px;border-bottom:1px solid var(--line);min-height:65px}.step-list li::before{content:counter(st,decimal-leading-zero);position:absolute;left:10px;top:16px;font-size:19px;font-weight:800;color:#0b8292}.table-scroll{overflow-x:auto;max-width:100%;margin:22px 0;border:1px solid var(--line);border-radius:10px;background:#fff}table{border-collapse:collapse;width:100%;min-width:570px;font-size:15px}caption{text-align:left;font-weight:700;padding:15px 16px;color:var(--ink)}th,td{padding:12px 15px;text-align:left;vertical-align:top;border-bottom:1px solid var(--line)}th{background:#eaf1f6;color:var(--ink)}tr:last-child td{border-bottom:none}.cols-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}.cols-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.info-panel{background:#fff;border:1px solid var(--line);padding:24px;border-radius:12px;min-width:0}.info-panel h3{margin-bottom:12px}.dark-panel{background:var(--deep);color:#e6f0f5;border-radius:12px;padding:26px}.dark-panel h2,.dark-panel h3{color:#fff}.content-band{padding:30px;background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.editorial-article{max-width:790px}.editorial-article section{margin-block:43px}.wide-feature{margin:30px 0}.faq-list{max-width:870px}.faq-list details{background:#fff;border:1px solid var(--line);border-radius:10px;margin:10px 0;padding:0 18px}.faq-list summary{cursor:pointer;color:var(--ink);font-weight:700;padding:14px 20px 14px 0}.faq-list details p{border-top:1px solid var(--line);padding:13px 0 18px}.related{margin-block:60px;background:#e9f8f8;padding:26px 30px;border-radius:12px}.related h2{font-size:23px}.related-links{display:flex;gap:14px;flex-wrap:wrap}.related-links a{display:inline-block;background:#fff;border:1px solid #cce2e6;border-radius:8px;text-decoration:none;font-weight:700;padding:9px 14px}.rule-reading{max-width:850px}.rule-reading>section{margin-block:45px}.faq-heading{margin-top:40px}.service-layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:44px;align-items:start}.service-content{min-width:0}.service-content section{margin-bottom:45px}.service-nav{background:#fff;border:1px solid var(--line);border-radius:12px;padding:22px;position:sticky;top:20px}.service-nav a{display:block;padding:9px 0}.site-footer{background:var(--footer);color:#dcecf5;margin-top:66px}.footer-grid{display:grid;grid-template-columns:1.3fr 1fr;gap:50px;padding-top:40px;padding-bottom:40px}.footer-brand{font-size:20px;font-weight:800;color:#fff;letter-spacing:.05em}.footer-brand span{font-size:15px;letter-spacing:0;margin-left:10px}.footer-small{font-size:13px;color:#c3d3df;max-width:590px}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px 18px;margin-top:9px}.footer-links a{color:#dcecf5;font-size:14px}.footer-bottom{padding:14px 0;border-top:1px solid #244152;font-size:12px;color:#c2d0da}.mobile-quick{display:none}.back-top{position:fixed;right:21px;bottom:22px;border:0;background:#102e46;color:#fff;width:43px;height:43px;border-radius:50%;cursor:pointer;box-shadow:0 3px 12px #0002}.back-top[hidden]{display:none}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #00a5b7;outline-offset:3px}.drawer-overlay,.mobile-drawer{visibility:hidden;pointer-events:none}.drawer-overlay{position:fixed;inset:0;background:#0b2539a6;opacity:0;z-index:50;transition:opacity .2s,visibility .2s}.drawer-overlay.is-open{visibility:visible;pointer-events:auto;opacity:1}.mobile-drawer{position:fixed;left:0;top:0;bottom:0;z-index:51;width:min(86vw,340px);overflow:auto;background:#fff;transform:translateX(-102%);transition:transform .22s,visibility .22s;padding:22px}.mobile-drawer.is-open{visibility:visible;pointer-events:auto;transform:translateX(0)}.drawer-top{display:flex;align-items:center;justify-content:space-between;color:var(--ink)}.drawer-close{border:0;background:#eaf1f6;border-radius:9px;width:42px;height:42px;font-size:29px;line-height:1}.drawer-group{border-top:1px solid var(--line);margin-top:20px;padding-top:13px}.drawer-group span{display:block;font-size:12px;font-weight:800;color:#188391;margin-bottom:7px}.drawer-group a{display:block;color:var(--ink);font-weight:700;text-decoration:none;padding:10px 8px;border-radius:6px}.drawer-group a:hover{background:var(--pale)}body.drawer-active{overflow:hidden}.small-muted{font-size:14px;color:var(--muted)}.rule-table{max-width:900px}.intro-divider{border-top:3px solid var(--cyan);padding-top:22px}.exhibit{display:grid;grid-template-columns:.9fr 1.1fr;gap:30px;align-items:center;margin:32px 0}.exhibit.reverse{grid-template-columns:1.1fr .9fr}.exhibit.reverse .media-frame{order:2}
@media(max-width:1200px){.wrap{width:calc(100% - 44px)}.nav-inner a{padding-inline:7px;font-size:14px}}@media(max-width:920px){.brandbar{height:62px;justify-content:space-between;gap:10px}.menu-toggle{display:flex;width:40px;height:40px;flex:0 0 40px;flex-direction:column;align-items:center;justify-content:center;gap:5px;border:1px solid var(--line);border-radius:9px;background:#fff}.menu-toggle span{width:19px;height:2px;background:var(--nav);display:block}.brand{position:absolute;left:50%;transform:translateX(-50%);max-width:40%}.brand-text{font-size:clamp(13px,3vw,21px)}.brand .media-frame--logo img{max-height:30px}.brand-desc,.desktop-nav{display:none}.register-link{font-size:13px;padding:7px 11px;min-height:39px}.noscript-nav{display:flex;flex-wrap:wrap;padding:12px 22px;gap:10px;background:var(--nav)}.noscript-nav a{color:white;font-size:13px}.hero h1{font-size:36px}.article-layout{grid-template-columns:minmax(0,1fr) 210px;gap:24px}.reading-path{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:760px){.hero,.feature-split,.feature-split.reverse,.focus-layout,.article-layout,.service-layout,.exhibit,.exhibit.reverse{grid-template-columns:1fr}.feature-split.reverse .media-frame,.exhibit.reverse .media-frame{order:0}.hero{margin-top:28px}.hero .media-frame{order:2}.aside-index,.service-nav{position:static}.service-nav{order:2}.cols-3,.text-grid{grid-template-columns:1fr 1fr}.focus-side{grid-template-columns:1fr 1fr}.mobile-quick{display:flex;justify-content:space-between;gap:8px;flex-wrap:wrap;margin-top:42px;padding:18px 0;border-top:1px solid var(--line)}.mobile-quick a{font-size:13px}.page-intro h1{font-size:30px}}@media(max-width:640px){.wrap{width:calc(100% - 32px)}body{font-size:15px;line-height:1.78}h1{font-size:29px}h2{font-size:22px}h3{font-size:18px}.hero h1{font-size:30px}.hero .lead,.lead{font-size:16px}.page-intro h1{font-size:27px}.section.section{margin-block:37px}.hero{gap:22px}.media-frame--hero{--media-limit:205px}.media-frame--feature{--media-limit:185px}.media-frame--card{--media-limit:145px}.media-frame--banner{--media-limit:135px}.media-frame--rules{--media-limit:175px}.media-frame--mobile{--media-limit:285px;max-width:250px}.topic-index,.cols-2,.cols-3,.text-grid,.focus-side,.footer-grid{grid-template-columns:1fr}.mini-lesson:nth-child(2),.mini-lesson:nth-child(3){margin-top:0}.focus-main{padding:23px}.reading-path{grid-template-columns:1fr}.path-step{padding:13px 18px}.footer-grid{gap:20px}.info-panel{padding:18px}.action-row{gap:8px}.button-link{padding:10px 14px}.related{padding:22px 18px}.section-nav a{font-size:13px}.service-nav{padding:18px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}
