:root{--bg:#F4F7FA;--surface:#fff;--soft:#EAF1F6;--mint:#E9F8F8;--nav:#102E46;--deep:#163C57;--teal:#13B8C5;--blue:#237BD3;--heading:#18364B;--text:#344C60;--muted:#64798A;--line:#DCE6ED;--footer:#0B2539;--width:1200px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:20px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}img{max-width:100%;height:auto}a{color:#1768ac;text-underline-offset:3px}a:hover{color:#0d8b9d}button{font:inherit;cursor:pointer}h1,h2,h3,h4{color:var(--heading);line-height:1.38;letter-spacing:-.018em}h1{font-size:clamp(2rem,3vw,2.25rem);margin:0 0 18px}h2{font-size:clamp(1.45rem,2.1vw,1.75rem);margin:0 0 18px}h3{font-size:1.2rem;margin:0 0 10px}p{margin:0 0 17px}ul,ol{padding-left:1.4em}li{margin-bottom:7px}figure{margin:0}section{scroll-margin-top:30px}.container{width:min(calc(100% - 56px),var(--width));margin-inline:auto}.reading{max-width:790px}.skip-link{position:absolute;top:-100px;left:12px;z-index:1000;background:#fff;padding:9px 16px}.skip-link:focus{top:8px}:focus-visible{outline:3px solid #167cdd;outline-offset:3px}.site-header{position:relative;z-index:10}.brand-bar{background:#fff;border-bottom:1px solid var(--line)}.brand-inner{display:flex;align-items:center;min-height:72px;gap:24px}.brand{display:flex;align-items:center;justify-content:flex-start;text-decoration:none;min-width:0}.brand-logo{width:auto;height:auto;max-height:38px;max-width:240px;object-fit:contain}.brand-fallback{font-size:24px;font-weight:800;color:var(--nav);line-height:1.15;white-space:nowrap}.brand-fallback small{display:block;font-size:9px;letter-spacing:.14em}.brand-note{color:var(--muted);font-size:13px}.entry-link{margin-left:auto;flex:none;display:inline-flex;align-items:center;justify-content:center;min-height:41px;padding:0 22px;background:var(--nav);color:#fff;border-radius:9px;text-decoration:none;font-weight:700;font-size:14px}.entry-link:hover{background:#195272;color:#fff}.desktop-nav{background:var(--nav)}.nav-row{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));align-items:stretch;min-height:50px}.nav-row a{min-width:0;display:flex;align-items:center;justify-content:center;position:relative;padding:9px 3px;color:#e2eff6;text-decoration:none;font-size:14px;font-weight:600;white-space:nowrap}.nav-row a[aria-current="page"]{font-weight:800;color:#fff}.nav-row a[aria-current="page"]:after{content:"";position:absolute;bottom:4px;left:29%;width:42%;height:3px;border-radius:2px;background:var(--teal)}.nav-row a:hover{background:#1a4864}.menu-toggle{display:none}.mobile-drawer,.drawer-backdrop{visibility:hidden;pointer-events:none}.nojs-nav{display:none}main{min-height:55vh}.page{padding-top:38px;padding-bottom:56px}.section{margin-top:58px}.section-head{max-width:780px;margin-bottom:24px}.eyebrow{display:block;font-size:12px;letter-spacing:.16em;font-weight:800;color:#087d89;margin-bottom:12px;text-transform:uppercase}.lead{font-size:17px;line-height:1.85;color:#455e70}.page-intro{padding:33px 0 8px;max-width:970px}.page-intro p{max-width:820px}.crumbs{color:var(--muted);font-size:13px;margin-bottom:12px}.crumbs a{color:inherit}.surface{background:var(--surface);border:1px solid var(--line);border-radius:14px}.soft{background:var(--soft)}.mint{background:var(--mint)}.dark{background:var(--deep);color:#ecf5fa}.dark h2,.dark h3{color:white}.panel{padding:26px}.grid-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.split{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:36px;align-items:center}.split-reverse{grid-template-columns:minmax(0,.87fr) minmax(0,1.13fr)}.split>* , .grid-2>* , .grid-3>*{min-width:0}.hero{padding:42px 0 14px}.hero .split{grid-template-columns:minmax(0,1.04fr) minmax(0,.96fr)}.hero h1{font-size:clamp(2rem,3.4vw,2.75rem)}.hero-copy p{max-width:590px}.btn-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:25px}.btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;background:var(--nav);color:#fff;padding:9px 20px;border-radius:9px;text-decoration:none;font-weight:700;font-size:14px}.btn:hover{color:#fff;background:#1e536d}.btn-outline{background:transparent;color:var(--nav);border:1px solid #9eafbd}.btn-outline:hover{background:#e6f4f5;color:var(--nav)}.media-frame{display:flex;align-items:center;justify-content:center;min-width:0;width:100%;padding:10px;border-radius:14px;background:var(--soft);border:1px solid var(--line)}.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-placeholder{width:100%;min-height:120px;display:grid;place-items:center;border:1px dashed #b8cbd5;border-radius:9px;color:#6e8595;font-size:13px;background:linear-gradient(135deg,#eaf1f6,#f7fafc)}.media-frame--hero .media-placeholder{min-height:220px}.media-frame--mobile .media-placeholder{min-height:260px}.topic-directory{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:44px}.topic-directory article{padding:19px 0 20px;border-bottom:1px solid var(--line)}.topic-directory h3{margin-bottom:4px}.topic-directory p{font-size:14px;color:var(--muted);margin:0}.focus-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:20px}.focus-main{padding:30px;border-radius:14px;background:var(--deep);color:#eaf4fa}.focus-main h3{font-size:24px;color:#fff}.focus-side{display:flex;flex-direction:column;gap:20px}.focus-side article{padding:23px;border:1px solid var(--line);background:#fff;border-radius:12px;flex:1}.focus-side p{font-size:14px}.article-text{max-width:790px}.article-text p{line-height:1.85}.article-text h2{margin-top:35px}.article-text h3{margin-top:26px}.aside-box{border-left:4px solid var(--teal);background:#eef6f8;padding:17px 21px;border-radius:0 10px 10px 0}.note{padding:19px 22px;background:#e9f8f8;border-left:4px solid #13b8c5;border-radius:0 10px 10px 0}.steps{counter-reset:step;display:grid;gap:14px}.step{position:relative;padding:20px 20px 20px 70px;background:#fff;border:1px solid var(--line);border-radius:12px}.step:before{counter-increment:step;content:counter(step,decimal-leading-zero);position:absolute;left:20px;top:20px;font-size:19px;font-weight:800;color:#0c929e}.step h3{margin-bottom:4px}.step p{margin:0}.tag{font-size:12px;text-transform:uppercase;letter-spacing:.12em;font-weight:800;color:#067e89}.table-scroll{max-width:100%;overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:#fff}table{border-collapse:collapse;width:100%;min-width:570px;font-size:14px;line-height:1.65}caption{text-align:left;font-weight:700;padding:14px 18px;color:var(--heading)}th,td{text-align:left;vertical-align:top;padding:15px 17px;border-bottom:1px solid var(--line)}thead th{background:#eaf1f6;color:#18364b}tbody tr:last-child td,tbody tr:last-child th{border-bottom:0}.chapter-grid{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:45px;align-items:start}.fact-aside{position:sticky;top:20px;padding:22px;border:1px solid var(--line);background:#fff;border-radius:12px}.fact-aside ul{padding-left:18px}.anchor-nav{display:flex;gap:9px;flex-wrap:wrap;margin:20px 0 28px}.anchor-nav a{display:inline-block;padding:7px 13px;background:#fff;border:1px solid var(--line);border-radius:30px;text-decoration:none;font-size:13px;font-weight:700}.editorial-band{padding:30px 34px;border-radius:14px}.quote{border-left:4px solid var(--teal);padding:15px 0 15px 26px;font-size:20px;color:var(--heading);font-weight:700}.gallery-grid{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:26px;align-items:start}.gallery-grid article:nth-child(even){padding-top:50px}.gallery-grid article{min-width:0}.gallery-grid h3{margin-top:14px}.faq-list{border-top:1px solid var(--line)}details{border-bottom:1px solid var(--line);padding:16px 0}summary{cursor:pointer;font-weight:700;color:var(--heading);line-height:1.55}details p{padding:12px 6px 0;margin:0}.service-layout{display:grid;grid-template-columns:245px minmax(0,1fr);gap:40px;align-items:start}.service-nav{background:#fff;border:1px solid var(--line);border-radius:12px;padding:20px;position:sticky;top:22px}.service-nav a{display:block;padding:8px 4px}.service-content{min-width:0}.service-content>section{margin-bottom:50px}.related{margin-top:58px;padding-top:26px;border-top:2px solid var(--line)}.related-links{display:flex;flex-wrap:wrap;gap:12px}.related-links a{display:inline-block;padding:10px 17px;background:#fff;border:1px solid var(--line);border-radius:9px;text-decoration:none;font-weight:700}.small{font-size:14px;color:var(--muted)}.mobile-shortcuts{display:none}.site-footer{background:var(--footer);color:#dcecf5;padding:42px 0 0;font-size:14px}.footer-grid{display:grid;grid-template-columns:2fr 1fr;gap:70px}.footer-brand{display:inline-block;background:#fff;padding:8px 12px;border-radius:8px;margin-bottom:12px}.footer-brand .brand-logo{max-height:30px}.footer-brand .brand-fallback{font-size:17px}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:7px 20px;margin-top:12px}.site-footer a{color:#e1f4fa}.footer-brand .brand-fallback{color:var(--nav)}.footer-bottom{border-top:1px solid #284557;padding:17px 0;margin-top:30px;color:#b6cad6;font-size:12px}.back-top{position:fixed;right:22px;bottom:22px;background:var(--nav);color:#fff;border:0;border-radius:50%;width:42px;height:42px;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .2s}.back-top.visible{opacity:1;visibility:visible;pointer-events:auto}
@media(max-width:1024px){.container{width:min(calc(100% - 44px),var(--width))}.section{margin-top:48px}.split{gap:25px}.brand-note{font-size:12px}}
@media(max-width:920px){.brand-inner{min-height:62px;display:grid;grid-template-columns:42px minmax(0,1fr) auto;gap:10px}.brand{justify-self:center}.brand-logo{max-height:30px;max-width:175px}.brand-fallback{font-size:18px}.brand-fallback small{font-size:7px}.brand-note,.desktop-nav{display:none}.entry-link{margin:0;min-height:39px;padding:0 12px;font-size:12px}.menu-toggle{display:flex;flex-direction:column;justify-content:center;gap:5px;align-items:center;width:40px;height:40px;border:1px solid var(--line);border-radius:8px;background:#fff}.menu-toggle span{display:block;width:19px;height:2px;background:var(--heading)}.drawer-backdrop{position:fixed;inset:0;background:rgba(13,31,44,.54);z-index:30;opacity:0;transition:opacity .2s}.mobile-drawer{position:fixed;z-index:31;inset:0 auto 0 0;width:min(86vw,340px);max-width:100%;height:100dvh;overflow:auto;background:#fff;transform:translateX(-105%);transition:transform .23s;padding:22px}.drawer-open{overflow:hidden}.drawer-open .drawer-backdrop,.drawer-open .mobile-drawer{visibility:visible;pointer-events:auto}.drawer-open .drawer-backdrop{opacity:1}.drawer-open .mobile-drawer{transform:translateX(0)}.drawer-top{display:flex;align-items:center;justify-content:space-between;padding-bottom:13px;border-bottom:1px solid var(--line);color:var(--heading)}.drawer-close{width:40px;height:40px;border:0;background:#eaf1f6;font-size:28px;border-radius:9px}.mobile-drawer nav a{display:block;color:var(--heading);text-decoration:none;padding:10px 5px;border-bottom:1px solid #eef2f5;font-weight:650}.drawer-group{font-size:12px;font-weight:800;color:#087e8a;letter-spacing:.12em;margin:23px 0 5px}.mobile-shortcuts{display:flex;justify-content:space-between;gap:8px;flex-wrap:wrap;padding:16px 0;border-top:1px solid var(--line)}.mobile-shortcuts a{font-size:13px;text-decoration:none;font-weight:700}.nojs-nav{display:flex;flex-wrap:wrap;gap:10px;padding:12px 0}.nojs-nav a{font-size:13px}}
@media(max-width:760px){.split,.split-reverse,.hero .split,.grid-2,.grid-3,.chapter-grid,.gallery-grid,.service-layout,.footer-grid,.focus-grid{grid-template-columns:1fr}.section{margin-top:38px}.hero{padding-top:25px}.hero .media-frame{margin-top:7px}.chapter-grid{gap:17px}.fact-aside,.service-nav{position:static}.gallery-grid article:nth-child(even){padding-top:0}.focus-side{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.service-content{order:0}.service-nav{order:1}.footer-grid{gap:22px}.page{padding-top:20px}.page-intro{padding-top:20px}}
@media(max-width:640px){body{font-size:15px;line-height:1.78}.container{width:calc(100% - 32px)}h1{font-size:clamp(25px,6vw,29px)}.hero h1{font-size:clamp(27px,7vw,32px)}h2{font-size:clamp(20px,5vw,23px)}h3{font-size:18px}.lead{font-size:15.5px}.section{margin-top:34px}.panel,.editorial-band{padding:19px}.focus-main{padding:22px}.focus-main h3{font-size:21px}.focus-side{grid-template-columns:1fr}.topic-directory{grid-template-columns:1fr}.topic-directory article{padding:14px 0}.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{padding:8px}.media-frame--hero .media-placeholder{min-height:150px}.gallery-grid{gap:17px}.btn-row{gap:8px}.btn{padding:8px 13px;font-size:13px}.entry-link{padding:0 9px}.brand-logo{max-height:27px;max-width:150px}.footer-links{grid-template-columns:repeat(2,minmax(0,1fr))}.back-top{right:14px;bottom:14px}.quote{font-size:18px}}
@media(max-width:380px){.brand-logo{max-width:130px}.brand-fallback{font-size:16px}.entry-link{font-size:11px;padding:0 8px}.brand-inner{gap:5px}.mobile-shortcuts a{font-size:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}