:root{--bg:#F6FAFC;--white:#fff;--tint:#EAF6FA;--tint2:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--deep:#174B78;--heading:#183A56;--text:#31485D;--muted:#687D8E;--border:#DCE9F0;--footer:#123653;--shell:1180px}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}a{color:var(--deep);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}button{font:inherit;cursor:pointer}h1,h2,h3{color:var(--heading);line-height:1.38;margin:0 0 .65em}h1{font-size:clamp(27px,3.3vw,42px);letter-spacing:-.025em}h2{font-size:clamp(21px,2.2vw,27px)}h3{font-size:clamp(17px,1.7vw,21px)}p{margin:.6em 0 1em}small{font-size:.85em}img{max-width:100%}.shell{width:min(var(--shell),calc(100% - 56px));margin-inline:auto}.reading{max-width:780px}.section{padding:56px 0}.section--white{background:#fff}.section--tint{background:var(--tint)}.eyebrow{font-size:13px;font-weight:700;color:#087E91;letter-spacing:.11em;margin:0 0 9px;text-transform:uppercase}.muted,.subtle{color:var(--muted)}.lead{font-size:17px;line-height:1.85}.section-heading{display:flex;justify-content:space-between;align-items:flex-end;gap:24px;margin-bottom:24px}.section-heading p{max-width:600px;margin:0}.section-heading h2{margin-bottom:4px}.text-link{font-weight:700;text-decoration:underline}.skip-link{position:absolute;top:-80px;left:12px;z-index:30;background:#fff;padding:8px}.skip-link:focus{top:8px}.site-header{background:#fff;border-bottom:1px solid var(--border)}.topbar{height:72px;display:flex;align-items:center;gap:22px}.brand{text-decoration:none;display:inline-flex;align-items:center;min-width:0;max-width:270px}.brand-fallback{font-size:24px;line-height:1.1;font-weight:800;color:var(--deep)}.brand-fallback 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a.active{color:#fff;border-bottom-color:var(--cyan)}.menu-toggle{display:none;width:40px;height:40px;padding:10px;border:1px solid var(--border);border-radius:8px;background:#fff;flex:none}.menu-toggle span{display:block;height:2px;background:var(--deep);margin:4px 0}.drawer-overlay{position:fixed;inset:0;background:rgba(11,37,59,.5);z-index:20;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer-overlay.is-open{visibility:visible;opacity:1;pointer-events:auto}.site-drawer{position:fixed;z-index:21;inset:0 auto 0 0;width:min(86vw,344px);max-width:100%;background:#fff;box-shadow:8px 0 30px #12365320;transform:translateX(-105%);visibility:hidden;pointer-events:none;transition:transform .22s,visibility .22s;overflow-y:auto}.site-drawer.is-open{transform:translateX(0);visibility:visible;pointer-events:auto}.drawer-head{display:flex;justify-content:space-between;align-items:center;padding:18px 22px;border-bottom:1px solid var(--border)}.drawer-close{width:40px;height:40px;border:0;background:var(--tint);font-size:26px;border-radius:9px}.drawer-body{padding:5px 22px 30px}.drawer-body a{display:block;padding:8px 4px;text-decoration:none;border-bottom:1px solid var(--border)}.drawer-group{font-weight:700;color:var(--deep);margin:19px 0 2px;font-size:14px}.drawer-open{overflow:hidden}.mobile-bottom{display:none}.back-top{position:fixed;right:20px;bottom:20px;background:var(--deep);color:#fff;border:0;border-radius:50%;width:44px;height:44px;z-index:10;box-shadow:0 6px 18px #12365330}.back-top[hidden]{display:none}.hero{padding:45px 0 36px;background:linear-gradient(115deg,#fff 0%,#fff 53%,#EAF6FA 100%)}.hero-grid{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:36px;align-items:center}.hero h1{max-width:650px}.hero-copy p{max-width:600px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:23px}.quickbar{padding:17px 0;background:#fff;border-bottom:1px solid var(--border)}.quick-groups{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.quick-group{display:flex;flex-wrap:wrap;gap:3px 12px;align-items:center;font-size:13px}.quick-group strong{color:var(--deep)}.quick-group a{white-space:nowrap}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{background:#fff;border:1px solid var(--border);padding:20px;border-radius:12px;min-width:0}.topic-card h3{font-size:18px;margin:0 0 7px}.topic-card p{font-size:14px;color:var(--muted);margin:0 0 12px}.topic-card a{font-weight:700}.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:34px;align-items:center}.split--editorial{grid-template-columns:minmax(0,2fr) minmax(0,1fr);align-items:stretch}.editorial-feature,.editorial-notes,.article-panel,.panel{background:#fff;border:1px solid var(--border);border-radius:14px;padding:26px}.editorial-feature{background:#EAF6FA}.editorial-notes article+article{border-top:1px solid var(--border);padding-top:20px;margin-top:20px}.eyeline{display:block;font-size:12px;letter-spacing:.08em;color:#087E91;font-weight:700;margin-bottom:8px}.mini-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.mini-block{padding:20px 0;border-top:3px solid var(--cyan)}.mini-block p{font-size:15px}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;counter-reset:step}.step{padding:22px 18px;background:#fff;border:1px solid var(--border);border-radius:10px}.step:before{counter-increment:step;content:'0' counter(step);display:block;font-size:20px;color:var(--blue);font-weight:800;margin-bottom:9px}.page-intro{padding:43px 0 26px}.page-intro p{max-width:820px}.page-intro.compact{padding:32px 0 18px}.prose h2{margin-top:1.7em}.prose h3{margin-top:1.3em}.prose ul,.prose ol{padding-left:1.4em}.prose li{padding-bottom:.4em}.prose p{margin:0 0 1.1em}.content-grid{display:grid;grid-template-columns:minmax(0,760px) minmax(0,240px);gap:35px;align-items:start}.aside-panel{background:var(--tint);padding:20px;border-radius:12px;position:sticky;top:18px}.aside-panel h3{margin:0 0 10px}.aside-panel a{display:block;margin:9px 0}.data-scroll{overflow-x:auto;max-width:100%}.data-table{border-collapse:collapse;width:100%;min-width:570px;background:#fff}.data-table th,.data-table td{border:1px solid var(--border);padding:13px 14px;text-align:left;vertical-align:top}.data-table th{background:var(--tint);color:var(--heading)}.inline-index{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0 30px}.inline-index a{padding:6px 12px;border:1px solid var(--border);background:#fff;border-radius:7px;text-decoration:none;font-size:14px}.feature-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.feature-list>*{background:#fff;border:1px solid var(--border);border-radius:12px;padding:22px;min-width:0}.feature-list p{font-size:15px}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}.gallery-grid article{min-width:0;background:#fff;border:1px solid var(--border);padding:20px;border-radius:12px}.gallery-grid p{font-size:15px}.quote-panel{padding:26px 30px;background:var(--tint);border-left:4px solid var(--cyan);border-radius:0 12px 12px 0}.related{display:flex;flex-wrap:wrap;gap:12px;margin:25px 0}.related a{padding:9px 14px;border:1px solid #BCD9E8;border-radius:7px;background:#fff;text-decoration:none;font-weight:700}.faq details{background:#fff;border:1px solid var(--border);border-radius:9px;margin:10px 0;padding:14px 18px}.faq summary{color:var(--heading);font-weight:700;cursor:pointer}.faq details p{margin:10px 0 0}.media{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;overflow:hidden;border-radius:14px;background:var(--tint);margin:0}.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{width:auto;height:38px;max-width:270px;background:transparent;overflow:visible}.media--logo img{height:100%;width:auto;max-width:100%;object-fit:contain}.media--portrait{max-width:320px;margin-inline:auto}.media--wide{height:auto;max-height:240px;aspect-ratio:2.8/1}.media--missing{background:linear-gradient(135deg,#EDF5F8,#E7F2F8);min-height:100px}.media--logo.media--missing{min-height:0}.site-footer{background:var(--footer);color:#EAF7FF;margin-top:40px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:55px;padding:43px 0 29px}.footer-grid p{max-width:390px;color:#BED5E4;font-size:14px}.footer-grid a{display:block;color:#EAF7FF;font-size:14px;margin:8px 0}.footer-grid strong{display:block;margin-bottom:12px}.footer-brand{font-size:22px!important;font-weight:800;text-decoration:none}.footer-brand span{display:block;font-size:10px;letter-spacing:.18em}.footer-bottom{border-top:1px solid #426982;padding:18px 0 25px;display:flex;align-items:center;justify-content:space-between;gap:20px}.footer-bottom p,.footer-bottom small{font-size:12px;color:#BED5E4;margin:0}
@media(max-width:1100px){.topic-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.channel-inner{gap:14px}.channel-nav a{font-size:13px}}
@media(max-width:980px){.shell{width:calc(100% - 44px)}.topbar{height:64px;justify-content:space-between;gap:12px}.menu-toggle{display:block}.topbar-tagline{display:none}.brand{margin-right:auto}.media--logo{height:30px}.channel-nav{display:none}.no-js .channel-nav{display:block}.no-js .channel-inner{overflow-x:auto;justify-content:flex-start}.hero-grid{gap:24px}.quick-groups{gap:12px}.quick-group{font-size:12px}.content-grid{grid-template-columns:minmax(0,1fr)}.aside-panel{position:static}.section{padding:43px 0}}
@media(max-width:760px){.hero-grid,.split,.split--editorial{grid-template-columns:1fr}.hero-grid .media{order:-1}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.mini-grid,.feature-list{grid-template-columns:1fr 1fr}.steps{grid-template-columns:1fr 1fr}.footer-grid{grid-template-columns:1fr 1fr;gap:25px}.footer-grid>div:first-child{grid-column:1/-1}.quick-groups{grid-template-columns:1fr}.quick-group{font-size:14px}.gallery-grid{grid-template-columns:1fr}}
@media(max-width:640px){body{font-size:15px;line-height:1.75}.shell{width:calc(100% - 32px)}h1{font-size:clamp(27px,7.3vw,31px)}h2{font-size:clamp(20px,5.5vw,23px)}h3{font-size:18px}.topbar{height:62px}.register-button{height:40px;min-height:40px;padding:7px 13px;font-size:13px}.brand-fallback{font-size:19px}.brand-fallback small{font-size:8px}.section{padding:33px 0}.hero{padding:24px 0 28px}.hero-copy .lead{font-size:16px}.hero-actions .button{font-size:14px;padding:10px 15px}.section-heading{display:block}.topic-grid{grid-template-columns:1fr 1fr;gap:10px}.topic-card{padding:15px}.topic-card h3{font-size:16px}.topic-card p{font-size:13px}.mini-grid,.feature-list{grid-template-columns:1fr}.steps{grid-template-columns:1fr 1fr}.step{padding:15px}.editorial-feature,.editorial-notes,.article-panel,.panel{padding:18px}.page-intro{padding:28px 0 18px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--mobile{height:290px;max-width:250px}.media--wide{max-height:155px}.footer-grid{padding:35px 0 20px}.footer-bottom{display:block}.footer-bottom small{display:block;margin-top:10px}.mobile-bottom{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;left:0;right:0;bottom:0;z-index:12;background:#fff;border-top:1px solid var(--border);padding-bottom:env(safe-area-inset-bottom);box-shadow:0 -4px 12px #12365311}.mobile-bottom a{text-align:center;padding:11px 2px;color:var(--deep);font-size:13px;text-decoration:none;font-weight:700}.mobile-bottom a.active{color:var(--blue);box-shadow:inset 0 3px var(--cyan)}body{padding-bottom:calc(49px + env(safe-area-inset-bottom))}.back-top{bottom:calc(68px + env(safe-area-inset-bottom));right:16px}.site-footer{margin-top:24px}}
@media(max-height:510px) and (max-width:640px){.mobile-bottom{position:static}.back-top{bottom:18px}body{padding-bottom:0}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}