*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:#F4F7FA;color:#344C60;font:16px/1.82 Arial,"PingFang SC","Microsoft YaHei",sans-serif}body.drawer-open{overflow:hidden}a{color:#1669aa;text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #13B8C5;outline-offset:3px}img{max-width:100%;height:auto}h1,h2,h3,h4{color:#18364B;line-height:1.4;margin:0 0 .75em;letter-spacing:-.015em}h1{font-size:clamp(28px,3vw,43px)}h2{font-size:clamp(22px,2.2vw,28px)}h3{font-size:20px}p{margin:.65em 0 1.05em}ul,ol{padding-left:1.45em}li{margin:.4em 0}section[id],article[id],h2[id]{scroll-margin-top:25px}.container{max-width:1200px;padding:0 28px;margin:0 auto;min-width:0}.site-main{padding-top:36px;padding-bottom:66px;min-height:60vh}.section{margin-top:58px}.muted{color:#64798A}.eyebrow{color:#087e8d;font-weight:800;text-transform:uppercase;font-size:13px;letter-spacing:.12em}.lead{font-size:17px;max-width:810px;color:#425a6c}.small{font-size:14px}.kicker{font-size:13px;color:#087d88;font-weight:700;letter-spacing:.06em}.skip-link{position:absolute;left:12px;top:-100px;background:#fff;padding:12px;z-index:999}.skip-link:focus{top:8px}.site-header{background:#fff;position:relative;z-index:20;box-shadow:0 1px 0 #DCE6ED}.desktop-top{min-height:72px;display:flex;align-items:center;gap:20px}.brand{display:flex;align-items:center;min-width:120px}.brand .media-frame{max-width:230px}.brand-desc{font-size:13px;color:#64798A}.brand-fallback{font-weight:900;color:#102E46;font-size:15px;letter-spacing:.13em}.brand .media-frame:not(.is-missing)+.brand-fallback,.mobile-brand .media-frame:not(.is-missing)+.brand-fallback{display:none}.signup{margin-left:auto;border-radius:10px;background:#13B8C5;color:#082b3e;font-weight:800;font-size:14px;padding:9px 20px;white-space:nowrap}.signup:hover{background:#22c9d4;text-decoration:none}.desktop-nav{background:#102E46}.nav-inner{display:flex;gap:0;justify-content:space-between}.nav-inner>a{position:relative;padding:12px 10px;color:#e9f5f8;font-weight:600;font-size:15px;white-space:nowrap}.nav-inner>a[aria-current]{color:#fff;font-weight:800}.nav-inner>a[aria-current]::after{content:"";position:absolute;background:#13B8C5;left:11px;right:11px;bottom:5px;height:3px;border-radius:5px}.mobile-top,.mobile-drawer,.drawer-overlay,.nojs-nav{display:none}.media-frame{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;padding:8px;border-radius:14px;background:#EAF1F6;overflow:visible}.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--wide{--media-limit:210px}.media-frame--logo{--media-limit:38px;background:transparent;padding:0;border-radius:0;width:auto}.media-frame.is-missing{min-height:88px;color:#64798A;border:1px dashed #bdcdd9;font-size:13px;text-align:center}.media-frame--logo.is-missing{min-height:32px;max-width:65px;padding:0;font-size:0}.media-frame--logo.is-missing span{display:none}.page-intro{border-bottom:1px solid #DCE6ED;padding:9px 0 28px;max-width:1000px}.page-intro h1{font-size:clamp(26px,3vw,36px)}.page-intro .lead{max-width:850px}.breadcrumbs{font-size:13px;color:#64798A;margin:0 0 22px}.breadcrumbs a{color:#516b80}.chapter-nav{display:flex;gap:10px;flex-wrap:wrap;margin:26px 0 28px;padding:12px;background:#EAF1F6;border:1px solid #DCE6ED;border-radius:12px}.chapter-nav a{padding:8px 14px;border-radius:8px;background:#fff;color:#18364B;font-weight:700;font-size:14px}.chapter-nav a:hover{background:#E9F8F8}.cover{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(0,1fr);align-items:center;gap:30px;padding:30px;background:#fff;border:1px solid #DCE6ED;border-radius:16px}.cover h1{font-size:clamp(29px,3.5vw,43px);margin-bottom:.4em}.cover .lead{font-size:17px}.button-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.btn{background:#102E46;color:#fff;padding:10px 18px;border-radius:9px;font-weight:700;font-size:14px;display:inline-block}.btn.secondary{background:#E9F8F8;color:#125f70}.btn:hover{text-decoration:none;filter:brightness(1.09)}.topic-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 28px}.topic-item{padding:20px 5px;border-top:1px solid #DCE6ED;min-width:0}.topic-item h3{margin:0 0 7px;font-size:19px}.topic-item p{margin:0 0 7px}.editorial-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:24px}.editorial-primary{padding:28px;background:#fff;border-left:4px solid #13B8C5;border-radius:0 12px 12px 0}.editorial-aside{display:grid;gap:14px}.note-card{background:#EAF1F6;border-radius:12px;padding:18px 20px}.note-card h3{font-size:18px}.split{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:28px;min-width:0}.split>*{min-width:0}.split.reverse> :first-child{order:2}.split.reverse> :last-child{order:1}.dark-band{padding:26px 30px;border-radius:14px;background:#163C57;color:#e8f4f9}.dark-band h2,.dark-band h3{color:#fff}.rule-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.rule-cards article{padding:22px;border:1px solid #DCE6ED;border-radius:13px;background:#fff}.rule-cards article:nth-child(2){transform:translateY(12px)}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;counter-reset:step}.steps>div{padding:17px 14px;border-top:3px solid #13B8C5;background:#fff;border-radius:0 0 9px 9px}.steps strong{display:block;color:#18364B}.numbered-flow{counter-reset:flow;list-style:none;padding-left:0;display:grid;gap:17px}.numbered-flow li{position:relative;padding:18px 18px 18px 72px;background:#fff;border:1px solid #DCE6ED;border-radius:12px;margin:0}.numbered-flow li::before{counter-increment:flow;content:counter(flow,decimal-leading-zero);position:absolute;left:20px;top:16px;color:#087e8d;font-size:23px;font-weight:900}.text-columns{columns:2;column-gap:32px}.text-columns>*{break-inside:avoid}.article-body{max-width:795px}.article-body p,.prose p{line-height:1.85}.knowledge-layout{display:grid;grid-template-columns:minmax(0,2.2fr) minmax(215px,.8fr);gap:28px;align-items:start}.knowledge-layout>*{min-width:0}.aside-index{background:#EAF1F6;border-radius:12px;padding:20px;position:sticky;top:18px}.aside-index a{display:block;padding:7px 0;border-top:1px solid #DCE6ED}.comparison{overflow-x:auto;max-width:100%;border:1px solid #DCE6ED;border-radius:12px;background:#fff}.comparison table{border-collapse:collapse;width:100%;min-width:570px;font-size:15px}.comparison th,.comparison td{border-bottom:1px solid #DCE6ED;text-align:left;padding:13px 16px;vertical-align:top}.comparison th{background:#EAF1F6;color:#18364B;font-weight:750}.comparison caption{text-align:left;padding:12px 16px;font-weight:700;color:#18364B}.comparison tr:last-child td{border:0}.mini-callout{background:#E9F8F8;border-left:4px solid #13B8C5;padding:14px 18px;margin:18px 0}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.matrix>article{padding:22px;background:#fff;border:1px solid #DCE6ED;border-radius:12px}.matrix h3{margin-bottom:10px}.gallery{display:grid;grid-template-columns:1fr 1fr;gap:34px}.gallery>article:nth-child(even){padding-top:42px}.gallery>article{min-width:0}.service-layout{display:grid;grid-template-columns:235px minmax(0,1fr);gap:36px;align-items:start}.service-layout .aside-index{position:sticky;top:22px}.faq-list{border-top:1px solid #DCE6ED}.faq details{background:#fff;border-bottom:1px solid #DCE6ED;padding:0 18px}.faq summary{cursor:pointer;font-weight:700;color:#18364B;padding:16px 12px;list-style:none}.faq summary::after{content:'＋';float:right;color:#087e8d}.faq details[open] summary::after{content:'－'}.faq details p{margin:0 12px 20px}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.related-link{display:flex;flex-direction:column;position:relative;padding:19px 36px 19px 18px;border:1px solid #DCE6ED;background:#fff;border-radius:11px;color:#344C60}.related-link strong{color:#18364B}.related-link span{font-size:14px}.related-link span:last-child{position:absolute;right:13px;top:15px;color:#087e8d}.site-footer{background:#0B2539;color:#DCECF5;padding:36px 0 17px;font-size:14px}.footer-layout{display:grid;grid-template-columns:1.8fr 1fr;gap:28px}.footer-layout p{max-width:680px}.footer-brand{font-weight:800;font-size:19px;color:#fff}.footer-layout nav{display:grid;grid-template-columns:1fr 1fr;gap:6px 10px;align-content:start}.footer-layout nav a{color:#DCECF5}.footer-bottom{padding-top:18px;margin-top:22px;border-top:1px solid #2b4c61;color:#b8c9d6}.mobile-quick{display:none}.back-top{position:fixed;right:18px;bottom:20px;width:43px;height:43px;border:0;border-radius:10px;background:#102E46;color:#fff;font-size:23px;z-index:10;cursor:pointer}.back-top[hidden]{display:none}@media(max-width:1024px){.container{padding-left:22px;padding-right:22px}.nav-inner>a{font-size:14px;padding-left:7px;padding-right:7px}}@media(max-width:920px){.desktop-top,.desktop-nav{display:none}.mobile-top{display:grid;grid-template-columns:44px minmax(0,1fr) auto;align-items:center;gap:12px;min-height:62px;padding:0 17px}.mobile-brand{justify-self:center;display:flex;align-items:center;min-width:0;max-width:170px}.mobile-brand .media-frame--logo{--media-limit:30px}.mobile-brand .brand-fallback{font-size:13px}.signup--mobile{font-size:12px;padding:7px 11px;margin-left:0}.menu-toggle{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:5px;width:40px;height:40px;border:1px solid #DCE6ED;border-radius:9px;background:#fff;cursor:pointer}.menu-toggle span{width:20px;height:2px;background:#102E46}.mobile-drawer{display:block;position:fixed;z-index:51;top:0;bottom:0;left:0;width:min(86vw,340px);overflow-y:auto;background:#fff;padding:20px;transform:translateX(-105%);visibility:hidden;transition:transform .22s ease,visibility .22s}.drawer-head{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid #DCE6ED;padding-bottom:10px}.drawer-close{height:40px;width:40px;background:#EAF1F6;border:0;border-radius:8px;font-size:26px;cursor:pointer}.drawer-group{color:#64798A;font-size:12px;font-weight:800;margin:21px 0 8px}.mobile-drawer>a{display:block;color:#18364B;font-weight:700;border-bottom:1px solid #EAF1F6;padding:11px 5px}.mobile-drawer>a[aria-current]{border-left:3px solid #13B8C5;padding-left:11px;background:#E9F8F8}.drawer-overlay{display:block;position:fixed;inset:0;z-index:50;background:rgba(7,24,38,.52);opacity:0;visibility:hidden;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer-open .mobile-drawer{transform:translateX(0);visibility:visible}.drawer-open .drawer-overlay{opacity:1;visibility:visible;pointer-events:auto}.nojs-nav{display:flex;gap:8px;flex-wrap:wrap;padding:10px 16px;background:#EAF1F6}.nojs-nav a{padding:4px 8px;color:#18364B}.site-main{padding-top:24px}.mobile-quick{display:flex;gap:6px 18px;flex-wrap:wrap;border-top:1px solid #DCE6ED;padding-top:16px;padding-bottom:18px;font-size:13px}}@media(max-width:760px){.cover,.editorial-grid,.split,.knowledge-layout,.gallery,.service-layout,.footer-layout{grid-template-columns:1fr}.cover{padding:20px}.editorial-aside{grid-template-columns:1fr 1fr}.split.reverse> :first-child,.split.reverse> :last-child{order:initial}.aside-index{position:static}.service-layout>main{order:0}.service-layout>.aside-index{order:1}.text-columns{columns:1}.matrix{grid-template-columns:1fr}.related-grid{grid-template-columns:1fr 1fr}.steps{grid-template-columns:1fr 1fr}.rule-cards{grid-template-columns:1fr}.rule-cards article:nth-child(2){transform:none}.gallery>article:nth-child(even){padding-top:0}.footer-layout nav{max-width:550px}}@media(max-width:640px){body{font-size:15px;line-height:1.78}.container{padding-left:16px;padding-right:16px}.site-main{padding-bottom:40px}.section{margin-top:36px}.cover{gap:14px}.cover h1{font-size:clamp(27px,7vw,32px)}.page-intro h1{font-size:clamp(25px,6vw,29px)}h2{font-size:21px}h3{font-size:18px}.lead,.cover .lead{font-size:15px}.topic-list,.editorial-aside,.related-grid{grid-template-columns:1fr}.editorial-primary,.dark-band{padding:18px}.steps{grid-template-columns:1fr}.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--wide{--media-limit:135px}.media-frame--logo{--media-limit:30px}.related-reading{margin-top:38px}.comparison table{font-size:14px}.comparison td,.comparison th{padding:10px 12px}.mobile-top{gap:7px;padding:0 12px}.signup--mobile{padding:6px 8px}.footer-layout nav{grid-template-columns:1fr 1fr}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}