:root{--bg:#F6FAFC;--surface:#fff;--soft:#EAF6FA;--soft2:#EDF4F8;--brand:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--title:#183A56;--text:#31485D;--muted:#687D8E;--line:#DCE9F0;--footer:#123653;--container:1180px;--shadow:0 12px 30px rgba(21,70,103,.055)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}body.drawer-open{overflow:hidden}a{color:var(--navy);text-decoration-thickness:1px;text-underline-offset:4px}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--sky);outline-offset:3px}img{max-width:100%;height:auto}h1,h2,h3,p{margin-top:0}h1,h2,h3{color:var(--title);line-height:1.38}h1{font-size:clamp(32px,3.3vw,42px);letter-spacing:-.025em}h2{font-size:clamp(22px,2.2vw,27px);margin-bottom:17px}h3{font-size:20px;margin-bottom:11px}p{margin-bottom:17px}small,.fine{font-size:13px}.container{width:min(var(--container),calc(100% - 56px));margin-inline:auto}.section{padding:54px 0}.section--soft{background:var(--soft)}.section--white{background:#fff}.eyebrow{display:block;font-weight:700;font-size:13px;color:#087d91;letter-spacing:.09em;margin-bottom:14px}.lead{font-size:17px;line-height:1.83;max-width:810px}.narrow{max-width:780px}.site-header{background:#fff;border-bottom:1px solid var(--line);position:relative;z-index:15}.topbar{height:72px;display:flex;align-items:center;gap:20px}.brand{display:flex;align-items:center;min-width:0;text-decoration:none}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:205px;object-fit:contain}.brand-text{font-weight:800;font-size:23px;line-height:1.1;color:var(--navy);white-space:nowrap}.brand-text small{display:block;font-size:9px;letter-spacing:.15em;margin-top:5px}.topbar-tagline{font-size:14px;color:var(--muted);margin:0 auto}.entry-button{display:inline-flex;align-items:center;justify-content:center;height:42px;padding:0 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56px;background:linear-gradient(120deg,#f6fafc,#edf8fb)}.hero-grid{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:46px;align-items:center}.hero h1{max-width:650px;margin:0 0 18px}.hero p{max-width:600px}.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:25px}.action{display:inline-flex;align-items:center;min-height:43px;border-radius:7px;padding:8px 20px;text-decoration:none;font-size:14px;font-weight:700;border:1px solid var(--navy)}.action--main{background:var(--navy);color:#fff}.action--main:hover{color:#fff;background:#0d6599}.action--outline{background:#fff;color:var(--navy)}.quicklinks{background:#fff;border-bottom:1px solid var(--line)}.quicklinks-inner{display:flex;flex-wrap:wrap;gap:12px 30px;padding:14px 0;font-size:13px}.quicklinks strong{color:var(--title)}.quicklinks a{margin-right:10px;text-decoration:none;border-bottom:1px solid var(--line)}.media{display:flex;justify-content:center;align-items:center;width:100%;min-width:0;overflow:hidden;border-radius:14px;background:var(--soft);border:1px solid var(--line)}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--hero{height:clamp(250px,26vw,330px)}.media--feature{height:250px}.media--card{height:170px}.media--banner{height:220px}.media--mobile{height:350px;max-width:320px}.media--football{height:240px}.media-placeholder{width:100%;height:100%;display:flex;align-items:center;justify-content:center;background:linear-gradient(130deg,#e7f4f8,#f3f8fb)}.placeholder-mark{width:22%;max-width:78px;aspect-ratio:1;border:2px solid #badde8;border-radius:22%;position:relative;transform:rotate(-8deg)}.placeholder-mark:before,.placeholder-mark:after{content:"";position:absolute;background:#badde8;border-radius:50%}.placeholder-mark:before{width:25%;height:25%;top:20%;right:20%}.placeholder-mark:after{width:54%;height:3px;bottom:28%;left:16%;transform:rotate(-28deg)}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:15px}.topic-card{display:block;min-width:0;background:#fff;border:1px solid var(--line);border-radius:11px;padding:22px;text-decoration:none;transition:border-color .2s,transform .2s}.topic-card:hover{border-color:var(--sky);transform:translateY(-2px)}.topic-card h3{font-size:18px}.topic-card p{color:var(--muted);font-size:14px;margin:0;line-height:1.7}.editorial-grid{display:grid;grid-template-columns:2fr 1fr;gap:18px}.story-main,.story-small,.panel{background:#fff;border:1px solid var(--line);border-radius:12px;padding:26px}.story-main{background:linear-gradient(145deg,#eaf6fa,#fff)}.story-main h3{font-size:24px}.story-side{display:grid;gap:18px}.story-small h3{font-size:18px}.story-small p{font-size:14px}.split{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));align-items:center;gap:46px}.split--reverse .media{order:-1}.section-intro{max-width:760px;margin-bottom:24px}.text-link{font-weight:700}.rule-grid,.three-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.rule-grid article,.three-grid article{padding:22px;background:#fff;border:1px solid var(--line);border-radius:11px}.rule-grid article h3,.three-grid article h3{font-size:18px}.rule-grid p,.three-grid p{font-size:15px}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;list-style:none;margin:0;padding:0;counter-reset:step}.steps li{padding:18px;background:#fff;border:1px solid var(--line);border-radius:10px;counter-increment:step}.steps li:before{content:counter(step,decimal-leading-zero);display:block;font-weight:800;color:#0a829a;font-size:24px}.related{padding:32px 0 66px}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}.related-link{padding:17px 19px;background:#fff;border:1px solid var(--line);border-radius:9px;text-decoration:none;font-weight:700}.article-section{padding:24px 0 34px;border-bottom:1px solid var(--line)}.article-section:last-child{border-bottom:0}.article-section p{max-width:780px}.article-section ul,.article-section ol{max-width:800px;padding-left:23px}.article-section li{margin-bottom:9px}.reading-layout{display:grid;grid-template-columns:minmax(0,760px) minmax(0,240px);gap:55px;align-items:start}.reading-layout article{min-width:0}.term-sidebar{background:var(--soft);border:1px solid var(--line);padding:22px;border-radius:12px;position:sticky;top:20px}.term-sidebar h2{font-size:20px}.term-sidebar dl{margin:0}.term-sidebar 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var(--line);border-radius:12px}.gallery-item h3,.gallery-item p{margin-left:5px;margin-right:5px}.gallery-item p{font-size:14px}.anchor-nav{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0 30px}.anchor-nav a{padding:8px 14px;border:1px solid var(--line);border-radius:7px;background:#fff;text-decoration:none;font-size:14px}.faq-list{border-top:1px solid var(--line)}details{padding:15px 0;border-bottom:1px solid var(--line)}summary{cursor:pointer;color:var(--title);font-weight:700;padding:3px 24px 3px 0}details p{margin:12px 0 0;max-width:830px}.site-footer{background:var(--footer);color:#eaf7ff;padding:40px 0 20px}.footer-grid{display:grid;grid-template-columns:1.4fr 1fr;gap:60px}.footer-brand{font-size:22px}.footer-brand small{font-size:10px;letter-spacing:.12em}.site-footer p,.site-footer .fine{color:#d1e3ef}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 20px;margin-top:10px}.site-footer a{color:#eaf7ff;font-size:14px}.footer-bottom{border-top:1px solid rgba(255,255,255,.2);display:flex;justify-content:space-between;gap:20px;padding-top:15px;margin-top:26px;font-size:13px}.back-to-top{position:fixed;right:20px;bottom:20px;width:43px;height:43px;border:0;border-radius:50%;background:var(--navy);color:white;cursor:pointer;opacity:0;visibility:hidden;transition:opacity .2s,visibility .2s;z-index:16}.back-to-top.visible{opacity:1;visibility:visible}
@media(max-width:980px){.container{width:calc(100% - 44px)}.topbar{height:64px;justify-content:space-between;position:relative}.menu-toggle{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;width:40px;height:40px;background:transparent;border:1px solid var(--line);border-radius:7px;cursor:pointer;flex-shrink:0}.menu-toggle span{display:block;width:19px;height:2px;background:var(--title)}.brand{position:absolute;left:50%;transform:translateX(-50%);max-width:calc(100% - 190px)}.brand img{max-height:30px;max-width:170px}.brand-text{font-size:19px}.brand-text small{font-size:8px}.topbar-tagline,.desktop-nav{display:none}.entry-button{margin-left:auto;height:40px;padding:0 13px;font-size:13px}.drawer-backdrop{display:block;position:fixed;inset:0;background:rgba(7,31,51,.45);z-index:40;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.mobile-drawer{display:block;position:fixed;z-index:41;inset:0 auto 0 0;width:min(86vw,344px);background:#fff;transform:translateX(-101%);transition:transform .25s;overflow-y:auto;padding:20px;visibility:hidden}.drawer-open .drawer-backdrop{visibility:visible;opacity:1;pointer-events:auto}.drawer-open .mobile-drawer{visibility:visible;transform:translateX(0)}.drawer-top{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding-bottom:13px}.drawer-close{border:1px solid var(--line);border-radius:6px;background:#fff;width:40px;height:40px;font-size:26px;color:var(--title);cursor:pointer}.drawer-group{padding:16px 0;border-bottom:1px solid var(--line)}.drawer-group h2{font-size:13px;color:var(--muted);margin:0 0 8px}.drawer-group a{display:block;padding:9px 0;text-decoration:none;font-weight:700}.hero-grid{gap:25px}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.reading-layout{grid-template-columns:minmax(0,1fr) 205px;gap:25px}}
@media(max-width:760px){.split,.hero-grid,.editorial-grid,.footer-grid,.reading-layout{grid-template-columns:1fr}.hero-grid{gap:25px}.hero .media{order:2}.hero-actions{margin-top:20px}.story-side{grid-template-columns:1fr 1fr}.split--reverse .media{order:0}.term-sidebar{position:static}.matrix,.rule-grid,.three-grid{grid-template-columns:1fr 1fr}.steps{grid-template-columns:1fr 1fr}.related-grid{grid-template-columns:1fr}.footer-grid{gap:20px}.gallery-grid{gap:16px}}
@media(max-width:640px){body{font-size:15px;line-height:1.78}.container{width:calc(100% - 32px)}h1{font-size:clamp(27px,7vw,31px)}h2{font-size:21px}h3{font-size:18px}.section{padding:34px 0}.page-heading{padding:29px 0 13px}.page-heading h1{font-size:clamp(25px,6vw,29px)}.hero{padding:30px 0}.hero .lead{font-size:15px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--mobile{height:290px;max-width:250px}.media--football{height:185px}.quicklinks-inner{gap:8px 20px}.quicklinks-inner>div{width:100%}.topic-grid,.gallery-grid,.matrix,.rule-grid,.three-grid,.story-side{grid-template-columns:1fr}.topic-card{padding:17px}.story-main,.story-small,.panel{padding:19px}.split{gap:22px}.steps{grid-template-columns:1fr 1fr}.steps li{padding:13px}.footer-bottom{flex-direction:column;gap:5px}.site-footer{padding-bottom:88px}.mobile-bottom{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;z-index:19;background:#fff;border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom);box-shadow:0 -3px 18px rgba(14,50,70,.07)}.mobile-bottom a{text-align:center;padding:10px 2px;min-height:48px;display:grid;place-items:center;text-decoration:none;font-size:13px;font-weight:700}.back-to-top{bottom:75px;right:13px}}
@media(max-height:480px) and (max-width:640px){.mobile-bottom{position:static}.site-footer{padding-bottom:20px}.back-to-top{bottom:16px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}

.no-js-nav{display:flex;gap:12px;flex-wrap:wrap;padding:12px 0}.no-js-nav a{font-size:14px;display:inline-block;padding:4px 8px;background:#eaf6fa;border-radius:5px}