:root{--bg:#F4F7FA;--white:#fff;--light:#EAF1F6;--mint:#E9F8F8;--navy:#102E46;--deep:#163C57;--cyan:#13B8C5;--blue:#237BD3;--heading:#18364B;--ink:#344C60;--muted:#64798A;--line:#DCE6ED;--footer:#0B2539;--ftext:#DCECF5}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}a{color:#11639d;text-decoration:none}a:hover{text-decoration:underline}button{font:inherit;cursor:pointer}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}h1,h2,h3,h4{color:var(--heading);line-height:1.37;margin:0 0 .65em;font-weight:750}h1{font-size:clamp(29px,3vw,42px)}h2{font-size:clamp(22px,2.4vw,28px)}h3{font-size:20px}p{margin:0 0 1.15em}ul,ol{padding-left:1.5em}li{margin:.35em 0}small{font-size:13px}.container{width:min(100% - 56px,1200px);margin-inline:auto}.skip-link{position:absolute;top:-70px;left:12px;background:#fff;padding:8px;z-index:1000}.skip-link:focus{top:8px}.site-header{background:var(--navy);color:#fff}.brandbar{background:var(--navy)}.brand-inner{min-height:72px;display:flex;align-items:center;gap:18px}.brand{display:inline-flex;align-items:center;min-width:0;max-width:240px;color:#fff;text-decoration:none}.brand .media-frame{border:0;background:transparent;padding:0;justify-content:flex-start}.brand .media-frame img{max-height:38px;max-width:200px}.brand-fallback{font-size:20px;font-weight:800;letter-spacing:.04em}.brand:has(img) .brand-fallback{display:none}.brand-note{font-size:13px;color:#cadce8;margin-right:auto}.brand-note i{font-style:normal;color:#6c9dbb;padding:0 8px}.entry-link{margin-left:auto;flex:none;background:var(--cyan);color:#062739!important;font-weight:750;line-height:1.3;padding:12px 21px;border-radius:10px}.entry-link:hover{text-decoration:none;background:#5ad6df}.primary-nav{border-top:1px solid #31516a;background:var(--navy)}.nav-row{height:50px;display:flex;gap:0;align-items:stretch;justify-content:space-between}.primary-nav a{display:flex;align-items:center;position:relative;color:#e8f1f5;font-size:15px;font-weight:550;padding:0 10px;white-space:nowrap}.primary-nav a[aria-current=page]{font-weight:800;color:#fff}.primary-nav a[aria-current=page]::after{content:"";height:3px;position:absolute;bottom:0;left:10px;right:10px;background:var(--cyan)}.primary-nav a:hover{text-decoration:none;color:#a7f7ff}.menu-toggle{display:none}.drawer-overlay,.mobile-drawer,.nojs-navigation,.mobile-shortcuts{display:none}.eyebrow{text-transform:uppercase;letter-spacing:.13em;color:#087f90;font-weight:800;font-size:12px;margin-bottom:12px}.section-head{display:flex;justify-content:space-between;align-items:baseline;gap:24px}.section-head p{color:var(--muted);font-size:14px}.page-intro{padding:48px 0 36px}.page-intro h1{font-size:clamp(27px,3vw,36px)}.lead{font-size:17px;max-width:840px;color:#53687a}.breadcrumbs{display:flex;align-items:center;gap:12px;padding-top:22px;font-size:13px;color:var(--muted)}.breadcrumbs a{color:var(--muted)}.section{margin-top:56px}.article-flow{max-width:800px}.article-flow p,.article-flow li{line-height:1.82}.article-flow h2,.article-flow h3{margin-top:1.55em}.article-flow h2:first-child{margin-top:0}.article-flow strong{color:var(--heading)}.hero{display:grid;grid-template-columns:minmax(0,52fr) minmax(0,48fr);gap:40px;align-items:center;margin-top:35px;padding:45px;background:#fff;border:1px solid var(--line);border-radius:16px}.hero h1{font-size:clamp(28px,3.2vw,44px);letter-spacing:-.025em}.hero p{font-size:17px}.hero .eyebrow{font-size:13px}.hero-media{min-width:0}.link-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.btn{display:inline-flex;align-items:center;justify-content:center;background:var(--navy);color:#fff;font-weight:700;padding:10px 20px;border-radius:9px;min-height:44px}.btn:hover{text-decoration:none;background:var(--deep)}.btn--outline{background:#eaf3f8;color:#163c57}.btn--outline:hover{background:#dceff2}.media-frame{margin:0;display:flex;align-items:center;justify-content:center;min-width:0;width:100%;padding:8px;border-radius:14px;background:var(--light)}.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--banner{--media-limit:210px}.media-frame--logo{--media-limit:38px}.media-missing{min-height:100px;border:1px dashed #c5d8e1;color:#738b98;font-size:13px;text-align:center}.media-missing.media-frame--hero{min-height:200px}.media-missing.media-frame--logo{min-height:0;display:none}.topics{display:grid;grid-template-columns:1fr 1fr;column-gap:55px}.topic-item{padding:21px 0;border-top:1px solid var(--line);display:grid;grid-template-columns:34px 1fr;gap:14px}.topic-item .num{color:#148b9a;font-size:14px;font-weight:800}.topic-item h3{font-size:19px;margin-bottom:6px}.topic-item p{font-size:15px;color:var(--muted);margin-bottom:9px}.topic-item a{font-size:14px;font-weight:700}.feature-asym{display:grid;grid-template-columns:2fr 1fr;gap:20px}.feature-main{background:var(--navy);color:#e8f1f7;padding:32px;border-radius:14px}.feature-main h3{color:#fff;font-size:25px}.feature-main a{color:#90edf2}.feature-main .eyebrow{color:#65d8e0}.feature-side{display:grid;gap:20px}.feature-side article,.simple-panel{background:#fff;border:1px solid var(--line);border-radius:14px;padding:24px}.feature-side article p{font-size:14px}.feature-side h3{font-size:18px}.split{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:40px}.split--reverse .media-frame{order:2}.dark-band{background:var(--navy);color:#e7f1f6;padding:32px;border-radius:14px}.dark-band h2,.dark-band h3{color:#fff}.lesson-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;align-items:start}.lesson-list article{border-left:3px solid var(--cyan);padding:17px 18px;background:white}.lesson-list article:nth-child(2){margin-top:24px}.lesson-list article:nth-child(3){margin-top:48px}.step-row{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0}.step-row article{border-top:3px solid var(--cyan);padding:20px 18px;background:#fff;border-right:1px solid var(--line)}.step-row article strong{display:block;color:#078a96;font-size:13px;margin-bottom:8px}.step-row article h3{font-size:17px}.step-row article p{font-size:14px}.section-nav{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:26px}.section-nav a{padding:8px 16px;background:#e7f0f5;border:1px solid var(--line);border-radius:8px;font-size:14px}.content-grid{display:grid;grid-template-columns:minmax(0,1fr) 245px;gap:50px;align-items:start}.aside-box{border-top:4px solid var(--cyan);padding:19px;background:#fff;position:sticky;top:20px}.aside-box h2{font-size:18px}.aside-box p,.aside-box li{font-size:14px}.aside-box a{display:block;padding:5px 0}.table-scroll{max-width:100%;overflow-x:auto;background:#fff;border:1px solid var(--line);border-radius:10px}table{border-collapse:collapse;width:100%;font-size:15px;min-width:560px}caption{text-align:left;font-weight:800;color:var(--heading);padding:16px 18px}th,td{padding:14px 17px;border-bottom:1px solid var(--line);vertical-align:top;text-align:left}th{background:#eaf1f6;color:var(--heading)}tr:last-child td{border-bottom:0}.full-bleed-table{margin:36px 0}.info-note{border-left:3px solid var(--cyan);padding:20px 24px;background:var(--mint);margin:22px 0}.numbered-blocks{counter-reset:n;display:grid;gap:13px}.numbered-blocks article{counter-increment:n;background:#fff;padding:22px;border-left:1px solid var(--line);display:grid;grid-template-columns:50px 1fr;gap:14px}.numbered-blocks article::before{content:counter(n,decimal-leading-zero);color:#0e8e9a;font-size:23px;font-weight:800}.numbered-blocks h3{margin:0 0 5px}.numbered-blocks p{margin-bottom:0}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.matrix article{background:#fff;border-top:4px solid var(--cyan);padding:24px}.matrix h3{font-size:21px}.gallery-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:30px}.gallery-grid article:nth-child(2){margin-top:42px}.gallery-grid article{background:#fff;padding:18px;border:1px solid var(--line);border-radius:12px}.gallery-grid h3{margin-top:15px}.rules-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:42px;align-items:start}.rules-index{position:sticky;top:20px;border:1px solid var(--line);border-radius:12px;padding:20px;background:#fff}.rules-index h2{font-size:17px}.rules-index a{display:block;padding:9px 0;border-bottom:1px solid var(--line)}.rules-index a:last-child{border-bottom:0}.service-layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:42px;align-items:start}.service-nav{background:#eaf1f6;padding:22px;border-radius:12px}.service-nav h2{font-size:18px}.service-nav a{display:block;padding:10px 0;border-bottom:1px solid #cedee8}.faq details{background:#fff;border:1px solid var(--line);border-radius:9px;margin:10px 0;padding:13px 19px}.faq summary{cursor:pointer;font-weight:750;color:var(--heading)}.faq details p{margin:13px 0 4px}.related{margin-top:70px;margin-bottom:65px}.related-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.related-links a{display:grid;grid-template-columns:1fr auto;align-items:start;gap:4px;background:#fff;padding:20px;border-top:3px solid var(--cyan);font-weight:800;color:var(--heading)}.related-links small{font-weight:400;color:var(--muted);grid-column:1}.related-links span{grid-column:2;grid-row:1;font-size:20px}.editorial{background:var(--mint);padding:25px 30px;border-left:4px solid var(--cyan);margin-top:48px}.site-footer{background:var(--footer);color:var(--ftext);margin-top:70px;padding:45px 0 17px}.footer-layout{display:grid;grid-template-columns:1.2fr 1fr;gap:70px}.footer-brand{font-size:21px;font-weight:800;color:#fff}.footer-brand small{display:block;font-size:11px;color:#9cc4d3;letter-spacing:.1em}.footer-layout p{max-width:630px}.footer-disclaimer{color:#bdd1dc;font-size:13px}.site-footer h2{color:#fff;font-size:17px}.footer-links{display:grid;grid-template-columns:repeat(2,1fr);gap:7px 12px}.footer-links a,.footer-bottom a{color:#deeff4;font-size:14px}.footer-bottom{border-top:1px solid #31536a;padding-top:17px;margin-top:30px;display:flex;justify-content:space-between;font-size:12px;color:#aec4d3}
@media(max-width:1024px){.container{width:calc(100% - 44px)}.hero{gap:22px;padding:30px}.content-grid{gap:26px}.section{margin-top:47px}}
@media(max-width:920px){.container{width:calc(100% - 44px)}.brand-inner{min-height:62px;display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:12px}.menu-toggle{display:flex;width:40px;height:40px;border:1px solid #7892a4;border-radius:9px;background:transparent;flex-direction:column;justify-content:center;align-items:center;gap:5px}.menu-toggle span{display:block;width:18px;height:2px;background:#fff}.brand{justify-self:center;max-width:175px}.brand .media-frame img{max-width:170px;max-height:30px}.brand-fallback{font-size:15px;white-space:nowrap}.brand-note,.primary-nav{display:none}.entry-link{font-size:13px;padding:10px 12px;min-height:40px;display:flex;align-items:center}.drawer-overlay{display:block;position:fixed;inset:0;background:rgba(4,24,37,.54);visibility:hidden;opacity:0;pointer-events:none;z-index:60;transition:opacity .2s}.mobile-drawer{display:block;position:fixed;top:0;bottom:0;left:0;width:min(86vw,340px);background:#fff;z-index:61;transform:translateX(-101%);visibility:hidden;overflow-y:auto;padding:20px 22px;transition:transform .2s,visibility .2s}.drawer-open .mobile-drawer{transform:translateX(0);visibility:visible}.drawer-open .drawer-overlay{visibility:visible;opacity:1;pointer-events:auto}.drawer-heading{display:flex;justify-content:space-between;align-items:center;color:var(--heading);font-size:21px;font-weight:800}.drawer-close{border:0;background:var(--light);border-radius:8px;width:40px;height:40px;font-size:28px;line-height:1}.drawer-group{font-size:12px;color:#728697;font-weight:800;letter-spacing:.13em;margin:22px 0 6px}.mobile-drawer>a{display:block;color:var(--heading);padding:10px 5px;border-bottom:1px solid var(--line)}.mobile-drawer>a[aria-current=page]{font-weight:800;border-left:3px solid var(--cyan);padding-left:11px}.mobile-shortcuts{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;margin-top:40px;padding:16px;background:#eaf1f6;border-radius:12px;font-size:13px}.nojs-navigation{display:flex;flex-wrap:wrap;gap:8px;padding-top:15px;padding-bottom:15px}.nojs-navigation a{padding:6px 12px;border:1px solid var(--line);background:#fff;border-radius:6px}}
@media(max-width:760px){.hero,.split,.feature-asym,.content-grid,.rules-layout,.service-layout,.gallery-grid,.footer-layout{grid-template-columns:1fr}.hero{margin-top:20px}.hero-media{grid-row:2}.split--reverse .media-frame{order:0}.topics{grid-template-columns:1fr}.feature-side{grid-template-columns:1fr 1fr}.aside-box,.rules-index{position:static}.service-layout .service-main{grid-row:1}.service-layout .service-nav{grid-row:2}.step-row{grid-template-columns:1fr 1fr}.gallery-grid article:nth-child(2){margin-top:0}.matrix{grid-template-columns:1fr}.related-links{grid-template-columns:1fr}.footer-layout{gap:20px}.site-footer{margin-top:50px}}
@media(max-width:640px){body{font-size:15px;line-height:1.8}.container{width:calc(100% - 32px)}h1{font-size:clamp(27px,7vw,32px)}h2{font-size:22px}h3{font-size:18px}.page-intro{padding:30px 0 18px}.page-intro h1{font-size:clamp(25px,6.5vw,29px)}.lead,.hero p{font-size:15px}.hero{padding:22px;gap:18px}.section{margin-top:36px}.section-head{display:block}.section-head p{margin-top:-9px}.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--banner{--media-limit:135px}.media-frame--logo{--media-limit:30px}.media-missing.media-frame--hero{min-height:125px}.feature-side,.lesson-list,.step-row{grid-template-columns:1fr}.lesson-list article:nth-child(n){margin-top:0}.numbered-blocks article{grid-template-columns:40px 1fr;padding:18px}.section-nav a{padding:6px 10px}.feature-main,.simple-panel{padding:21px}.related{margin-top:45px}.footer-bottom{gap:10px;flex-wrap:wrap}.footer-links{gap:4px}}
@media(max-width:360px){.brand-inner{gap:6px}.brand-fallback{font-size:13px}.entry-link{padding:9px;font-size:12px}.container{width:calc(100% - 28px)}.hero{padding:16px}.link-actions a{width:100%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}
