:root{--bg:#F6FAFC;--white:#fff;--tint:#EAF6FA;--tint2:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--title:#183A56;--text:#31485D;--muted:#687D8E;--line:#DCE9F0;--foot:#123653}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:135px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-x:hidden}body.drawer-open{overflow:hidden}a{color:var(--navy);text-underline-offset:4px}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}img{max-width:100%;height:auto}h1,h2,h3{color:var(--title);line-height:1.38;letter-spacing:-.025em}h1{font-size:clamp(32px,3.35vw,42px);margin:10px 0 21px}h2{font-size:26px;margin:0 0 17px}h3{font-size:20px;margin:0 0 10px}p{margin:0 0 17px}section[id],article[id]{scroll-margin-top:140px}.container{width:min(100% - 56px,1180px);margin:0 auto}.narrow{max-width:780px}.section{margin-top:60px;margin-bottom:60px}.section-head{margin-bottom:22px}.section-head p{max-width:700px}.eyebrow{font-size:13px;font-weight:800;letter-spacing:.13em;color:#0E8B9E;text-transform:uppercase}.site-header{position:relative;z-index:15;background:#fff}.topbar{height:72px;display:flex;align-items:center;gap:24px}.brand{display:flex;align-items:center;gap:10px;min-width:160px;text-decoration:none}.brand-text{font-size:17px;color:var(--navy);font-weight:800;letter-spacing:.04em;white-space:nowrap}.brand-text b{color:#1597B5}.brand .media--logo{height:38px;max-width:150px;min-width:0;flex:0 1 auto;background:transparent}.brand .media--placeholder{width:42px;min-width:42px;background:var(--tint)}.top-tagline{margin:0 auto;color:var(--muted);font-size:14px}.entry-button{border-radius:8px;background:var(--navy);color:white;text-decoration:none;white-space:nowrap;font-weight:700;padding:9px 22px;display:inline-flex;align-items:center;min-height:42px}.entry-button:hover{background:#20659a;color:white}.desktop-nav{background:var(--navy)}.nav-inner{display:flex;align-items:stretch;justify-content:space-between;gap:4px;min-height:48px}.nav-inner a{display:flex;align-items:center;justify-content:center;text-decoration:none;color:#edfaff;font-size:14px;font-weight:600;padding:8px 12px;border-bottom:3px solid transparent;white-space:nowrap}.nav-inner a:hover,.nav-inner a.active{color:#fff;background:#20628e;border-color:var(--cyan)}.skip-link{position:absolute;top:-100px;left:12px;background:white;z-index:100;padding:8px}.skip-link:focus{top:8px}.menu-toggle{display:none}.mobile-drawer,.drawer-backdrop{visibility:hidden;pointer-events:none}.quick-strip{background:var(--tint2);border-bottom:1px solid var(--line)}.quick-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;padding-top:10px;padding-bottom:10px}.quick-grid 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#dceef2}.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--logo{border:0;border-radius:0;height:38px;background:transparent}.media--wide{background:#eef8fa}.media--portrait{max-width:300px;margin:auto}.media--placeholder{background:linear-gradient(135deg,#EAF6FA,#EDF4F8);position:relative}.media--placeholder:after{content:'';width:34%;height:34%;max-width:85px;max-height:85px;border:2px solid #d2e7ef;border-radius:50%;opacity:.7}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{background:white;border:1px solid var(--line);padding:22px;border-radius:10px;text-decoration:none;display:block;min-width:0}.topic-card:hover{border-color:var(--cyan);transform:translateY(-2px)}.topic-card .number{color:#0d9bb0;font-size:12px;font-weight:800}.topic-card h3{margin:7px 0;font-size:18px}.topic-card p{font-size:14px;line-height:1.7;color:var(--muted);margin:0}.editor-grid{display:grid;grid-template-columns:2fr 1fr;gap:18px}.panel{background:white;padding:25px;border:1px solid var(--line);border-radius:12px;min-width:0}.panel--tint{background:var(--tint)}.panel h3{margin-top:0}.editor-side{display:grid;gap:18px}.editor-side .panel{padding:22px}.section-link{display:inline-block;font-weight:700;margin-top:8px;text-decoration-thickness:1px}.split-feature{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:42px}.split-feature--reverse .media{order:-1}.feature-text p{max-width:600px}.rule-grid,.three-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.rule-grid article{padding:23px;border-left:3px solid var(--cyan);background:white;border-radius:6px}.rule-grid .rule-icon{font-size:27px;color:#098caa}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;counter-reset:steps}.steps article{position:relative;padding:20px;background:var(--tint2);border-radius:10px}.steps article:before{counter-increment:steps;content:'0' counter(steps);font-size:22px;font-weight:800;color:#1294aa}.steps h3{font-size:17px;margin:9px 0}.notice{padding:22px 26px;border-left:4px solid var(--navy);background:var(--tint2);border-radius:8px}.page-intro{padding:44px 0 22px}.page-intro h1{font-size:clamp(28px,3vw,36px)}.page-intro .intro{max-width:800px;font-size:17px}.article-stack{display:grid;gap:24px}.article-stack article{padding-bottom:23px;border-bottom:1px solid var(--line)}.article-stack article:last-child{border:0}.content-grid{display:grid;grid-template-columns:minmax(0,760px) minmax(210px,240px);gap:40px;align-items:start}.article-text{min-width:0}.side-note{background:var(--tint);padding:22px;border-radius:12px;position:sticky;top:22px}.side-note ul{padding-left:20px;margin:0}.side-note li{margin-bottom:9px}.table-wrap{max-width:100%;overflow-x:auto;border:1px solid var(--line);border-radius:10px;background:white}table{width:100%;border-collapse:collapse;min-width:560px;font-size:15px}th,td{padding:15px 17px;vertical-align:top;border-bottom:1px solid var(--line);text-align:left}th{background:var(--tint);color:var(--title)}tbody tr:last-child td{border-bottom:0}.format-steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.format-steps article{padding:23px;background:white;border-top:3px solid var(--cyan);border-radius:9px}.badge-inline{color:#0d869c;font-weight:800;font-size:13px}.list-plain{padding-left:21px}.list-plain li{padding:5px 0}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.matrix .panel{border-top:4px solid var(--cyan)}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:21px}.gallery-card{padding:17px;background:white;border:1px solid var(--line);border-radius:12px}.gallery-card h3{margin:16px 6px 7px}.gallery-card p{margin:0 6px 8px;font-size:14px}.anchor-index{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0 28px}.anchor-index a{background:var(--tint);padding:7px 13px;border-radius:6px;text-decoration:none;font-weight:700;font-size:14px}.related-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.related-list a{background:white;border:1px solid var(--line);border-radius:9px;padding:18px;display:flex;justify-content:space-between;align-items:center;text-decoration:none;font-weight:700}.related-list a:hover{border-color:var(--cyan)}.faq-list{border-top:1px solid var(--line)}.faq-list details{background:white;border-bottom:1px solid var(--line);padding:0 20px}.faq-list summary{padding:17px 0;cursor:pointer;font-weight:700;color:var(--title)}.faq-list details p{color:var(--text);padding:0 20px 15px 0}.site-footer{background:var(--foot);color:#EAF7FF;margin-top:70px;padding-top:52px;font-size:14px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:50px}.footer-brand{font-size:22px;font-weight:800}.footer-brand span{display:block;font-size:13px;letter-spacing:.12em}.site-footer h2{font-size:16px;color:white}.site-footer a{color:#EAF7FF}.footer-links{display:grid;gap:7px}.muted-footer{color:#C1D5E4;font-size:13px;max-width:520px}.footer-bottom{border-top:1px solid #34566f;display:flex;justify-content:space-between;gap:16px;padding:20px 0;margin-top:35px;color:#C1D5E4;font-size:12px}.mobile-bottom{display:none}.back-top{position:fixed;right:20px;bottom:20px;opacity:0;pointer-events:none;transition:opacity 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@media(max-width:760px){.container{width:min(100% - 32px,1180px)}.hero{padding:32px 0}.hero-grid,.split-feature,.highlight-row,.editor-grid,.content-grid{grid-template-columns:1fr}.hero-copy{order:0}.hero-grid>.media{order:-1}.split-feature--reverse .media{order:0}.side-note{position:static}.rule-grid,.matrix,.format-steps,.steps,.related-list{grid-template-columns:1fr 1fr}.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:first-child{grid-column:1/-1}.page-intro{padding-top:32px}.mobile-bottom{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;z-index:11;background:#fff;border-top:1px solid var(--line);padding:6px 5px calc(6px + env(safe-area-inset-bottom));box-shadow:0 -2px 10px #174b7810}.mobile-bottom a{text-align:center;text-decoration:none;font-size:13px;font-weight:700;padding:8px 0}.site-footer{padding-bottom:76px}.back-top{bottom:79px}}
@media(max-width:640px){body{font-size:15px;line-height:1.75}h1{font-size:30px}h2{font-size:22px}h3{font-size:18px}.page-intro h1{font-size:27px}.hero h1{font-size:29px}.lead,.page-intro .intro{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--logo{height:30px}.section{margin-top:34px;margin-bottom:34px}.panel,.topic-card{padding:17px}.topic-grid{gap:10px}.topic-card h3{font-size:16px}.topic-card p{font-size:13px}.rule-grid,.matrix,.format-steps,.steps,.related-list,.gallery-grid,.three-grid{grid-template-columns:1fr}.footer-grid{gap:20px}.footer-bottom{flex-direction:column}.brand-text{font-size:12px}.brand .media--logo{max-width:94px}.entry-button{padding:5px 10px;font-size:12px}.actions{gap:9px}.btn{padding:9px 14px;font-size:14px}.site-footer{margin-top:45px}}
@media(max-height:480px) and (max-width:760px){.mobile-bottom{position:static}.site-footer{padding-bottom:0}.back-top{bottom:20px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}