:root{--bg:#F4F7FA;--paper:#fff;--soft:#EAF1F6;--mint:#E9F8F8;--navy:#102E46;--deep:#163C57;--teal:#13B8C5;--blue:#237BD3;--heading:#18364B;--text:#344C60;--muted:#64798A;--line:#DCE6ED;--footer:#0B2539;font-family:Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text);background:var(--bg)}*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:18px}body{margin:0;min-width:0;overflow-x:hidden;font-size:16px;line-height:1.8}body.drawer-open{overflow:hidden}a{color:#1269b7;text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--teal);outline-offset:3px}img{max-width:100%;height:auto}h1,h2,h3{color:var(--heading);line-height:1.37;margin:0 0 18px}h1{font-size:clamp(29px,3vw,42px)}h2{font-size:clamp(22px,2.2vw,27px)}h3{font-size:19px}p{margin:0 0 16px}ul,ol{padding-left:1.4em}li+li{margin-top:8px}.wrap{width:min(100% - 56px,1200px);margin-inline:auto;min-width:0}.reading{max-width:800px}.section{margin-block:60px}.eyebrow{font-size:12px;font-weight:800;letter-spacing:.16em;text-transform:uppercase;color:#138a98;margin-bottom:11px}.section-heading{margin-bottom:24px}.section-heading p:last-child{max-width:700px}.section-label{font-size:12px;color:#16818b;text-transform:uppercase;font-weight:bold;letter-spacing:.12em}.site-header{position:relative;z-index:15}.brand-bar{background:#fff}.brand-inner{height:72px;display:flex;align-items:center;gap:20px;min-width:0}.brand{display:inline-flex;align-items:center;flex-shrink:0;min-width:0}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:245px;object-fit:contain}.brand-fallback{font-weight:800;font-size:23px;color:var(--navy);white-space:nowrap}.brand-fallback small{font-size:9px;letter-spacing:.12em;display:block;line-height:1}.brand-note{font-size:13px;color:var(--muted);border-left:1px solid 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a[aria-current=page]:after{content:"";position:absolute;bottom:4px;left:30%;width:40%;height:3px;background:var(--teal);border-radius:10px}.mobile-toggle,.mobile-drawer,.mobile-quick{display:none}.skip-link{position:absolute;left:12px;top:-70px;z-index:99;background:#fff;padding:10px}.skip-link:focus{top:10px}.drawer-overlay[hidden]{display:none!important}.drawer-overlay{position:fixed;inset:0;background:rgba(9,26,39,.56);z-index:25;visibility:hidden;pointer-events:none;opacity:0;transition:opacity .2s}.drawer-overlay.is-open{visibility:visible;pointer-events:auto;opacity:1}.page-heading{background:linear-gradient(100deg,#fff,#edf5f7);padding:45px 0 42px;border-bottom:1px solid var(--line)}.page-heading h1{font-size:clamp(26px,2.8vw,35px);max-width:950px}.page-lead{font-size:17px;max-width:900px;line-height:1.82;margin:0}.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:23px}.article-section{margin:42px 0 55px}.article-section h2{padding-bottom:11px;border-bottom:1px solid var(--line)}.article-section h3{margin-top:27px}.article-section p{max-width:850px}.paper{background:#fff;border:1px solid var(--line);border-radius:14px;padding:26px}.soft-panel{background:var(--soft);border-radius:14px;padding:25px}.mint-panel{background:var(--mint);border-radius:14px;padding:25px}.dark-panel{background:var(--deep);border-radius:15px;padding:28px;color:#eaf5fa}.dark-panel h2,.dark-panel h3{color:#fff}.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:38px;align-items:center}.split>*{min-width:0}.split--wide{grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr)}.split--reverse{grid-template-columns:minmax(0,.85fr) minmax(0,1.15fr)}.feature-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:22px;align-items:stretch}.feature-grid>*{min-width:0}.feature-grid aside article+article{margin-top:15px}.media-frame{width:100%;min-width:0;display:flex;align-items:center;justify-content:center;margin:0;padding:9px;background:var(--soft);border-radius:13px;overflow:hidden}.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-placeholder{min-height:110px;display:grid;place-items:center;width:100%;padding:25px;border:1px dashed #b7cbd7;border-radius:10px;color:#64798a;text-align:center;font-size:13px}.media-frame--hero .media-placeholder{min-height:180px}.button-row{display:flex;flex-wrap:wrap;gap:11px;margin-top:23px}.button{display:inline-block;border-radius:8px;background:var(--navy);padding:10px 18px;color:#fff;font-weight:700}.button:hover{text-decoration:none;background:var(--deep)}.button.secondary{background:#e5f6f7;color:#125967}.home-hero{padding:52px 0 30px;background:#fff}.home-hero h1{font-size:clamp(28px,3.6vw,43px)}.home-hero .lead{font-size:18px;color:var(--heading)}.topic-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 35px;border-top:2px solid var(--navy)}.topic-item{min-width:0;display:grid;grid-template-columns:36px 1fr;gap:12px;padding:21px 0;border-bottom:1px solid var(--line)}.topic-item .index{font-size:14px;color:#0d8d98;font-weight:800}.topic-item h3{margin:0 0 7px;font-size:19px}.topic-item p{font-size:15px;margin:0 0 8px}.topic-item a{font-weight:700}.focus-primary{background:var(--navy);color:#e9f4f9;border-radius:14px;padding:30px}.focus-primary h3{font-size:25px;color:#fff}.focus-primary a{color:#7fe9e8}.focus-side{background:#fff;border:1px solid var(--line);padding:23px;border-radius:12px}.focus-side h3{font-size:19px}.focus-side p{font-size:15px}.step-list{counter-reset:stage;list-style:none;padding:0;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}.step-list li{position:relative;background:#fff;border:1px solid var(--line);border-top:4px solid var(--teal);padding:22px;border-radius:8px;min-width:0;margin:0}.step-list li::before{counter-increment:stage;content:'0' counter(stage);display:block;font-weight:800;color:#138d9b;font-size:13px;margin-bottom:7px}.step-list strong{display:block;color:var(--navy)}.step-list p{font-size:14px;margin-top:8px}.rule-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;align-items:start}.rule-cards article{border:1px solid var(--line);background:#fff;border-radius:12px;padding:24px;min-width:0}.rule-cards article:nth-child(2){margin-top:23px}.rule-cards article:nth-child(3){margin-top:46px}.rule-cards h3{font-size:18px}.editor-note{border-left:4px solid var(--teal);background:#fff;padding:22px 26px}.anchor-nav{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}.anchor-nav a{padding:8px 14px;border:1px solid #b9d2df;border-radius:7px;background:#fff;color:var(--heading);font-size:14px;font-weight:700}.anchor-nav a:hover{text-decoration:none;border-color:var(--teal)}.layout-sidebar{display:grid;grid-template-columns:minmax(0,1fr) 240px;gap:44px;align-items:start}.layout-sidebar>*{min-width:0}.aside-note{background:var(--soft);padding:19px;border-radius:10px;font-size:14px;position:sticky;top:18px}.aside-note h3{font-size:17px}.table-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:10px;background:#fff;margin:24px 0}.data-table{width:100%;min-width:540px;border-collapse:collapse;text-align:left}.data-table caption{text-align:left;color:var(--muted);font-size:13px;padding:12px 16px}.data-table th,.data-table td{border-bottom:1px solid var(--line);padding:14px 16px;vertical-align:top}.data-table thead th{background:#eaf1f6;color:var(--heading)}.data-table tr:last-child td{border-bottom:0}.reading-list{padding-left:22px}.reading-list li{padding:8px 0}.numbered-notes{display:grid;gap:14px;counter-reset:item}.numbered-notes article{counter-increment:item;display:grid;grid-template-columns:45px 1fr;gap:18px;border-bottom:1px solid var(--line);padding:13px 0}.numbered-notes article::before{content:counter(item,decimal-leading-zero);color:#148e9b;font-weight:800}.numbered-notes h3{margin:0 0 5px}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.matrix>*{min-width:0;background:#fff;border:1px solid var(--line);border-radius:12px;padding:21px}.matrix h3{color:var(--deep)}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px;align-items:start}.gallery-grid>*{min-width:0}.gallery-grid article:nth-child(even){margin-top:38px}.gallery-grid h3{margin-top:15px}.gallery-grid p{font-size:15px}.faq-list{border-top:1px solid var(--line)}.faq-list details{background:#fff;border-bottom:1px solid var(--line);padding:0 18px}.faq-list summary{padding:17px 0;cursor:pointer;font-weight:700;color:var(--heading)}.faq-list details p{padding:0 0 19px;margin:0;max-width:850px}.help-layout{display:grid;grid-template-columns:260px minmax(0,1fr);gap:35px;align-items:start}.help-layout>*{min-width:0}.help-nav{background:var(--navy);color:#fff;border-radius:12px;padding:22px;position:sticky;top:15px}.help-nav h2{color:#fff;font-size:19px}.help-nav a{display:block;color:#d9f1fa;padding:6px 0}.related{border-top:1px solid var(--line);padding-top:35px}.related-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}.related-links a{display:flex;justify-content:space-between;gap:10px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px 17px;font-weight:700;color:var(--heading)}.related-links a:hover{text-decoration:none;border-color:var(--teal)}.site-footer{margin-top:55px;background:var(--footer);color:#dcecf5;padding:42px 0 23px}.footer-top{display:flex;justify-content:space-between;gap:25px}.footer-brand{font-weight:800;color:#fff;font-size:24px;margin:0 0 3px}.footer-brand span{font-size:11px;letter-spacing:.12em;color:#8fd5dd}.footer-top nav{display:flex;align-items:center;flex-wrap:wrap;gap:18px}.site-footer a{color:#e5f3fa}.footer-bottom{border-top:1px solid #345268;margin-top:24px;padding-top:17px;font-size:13px;color:#c3d9e5}.footer-bottom p{margin-bottom:8px}.muted{color:var(--muted)}.small{font-size:14px}
@media(max-width:1200px){.wrap{width:min(100% - 44px,1200px)}.nav-links a{padding-inline:6px;font-size:14px}}
@media(max-width:920px){.wrap{width:min(100% - 44px,1200px)}.brand-inner{height:62px;display:grid;grid-template-columns:42px minmax(0,1fr) auto;gap:10px}.brand{justify-self:center}.brand img{max-height:29px;max-width:min(36vw,185px)}.brand-fallback{font-size:18px}.brand-fallback small{font-size:7px}.brand-note,.desktop-nav{display:none}.mobile-toggle{width:40px;height:40px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:5px;background:#eef3f7;border:1px solid var(--line);border-radius:7px;cursor:pointer}.mobile-toggle span{display:block;width:19px;height:2px;background:var(--navy)}.register-link{font-size:13px;margin:0;padding:9px 11px;min-height:39px;display:grid;place-items:center}.mobile-drawer{display:block;position:fixed;z-index:30;top:0;bottom:0;left:0;width:min(86vw,340px);background:#fff;overflow-y:auto;padding:22px;transform:translateX(-102%);visibility:hidden;transition:transform .2s,visibility .2s;box-shadow:4px 0 18px #0002}.mobile-drawer.is-open{transform:translateX(0);visibility:visible}.drawer-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px;color:var(--heading)}.drawer-close{background:var(--soft);color:var(--heading);font-size:26px;line-height:1;border:0;width:40px;height:40px;border-radius:8px;cursor:pointer}.drawer-group{color:var(--muted);font-size:12px;font-weight:800;margin:17px 0 4px;letter-spacing:.1em}.mobile-drawer a{display:block;padding:10px 9px;border-bottom:1px solid var(--line);color:var(--heading);font-weight:650}.noscript-nav{display:flex;flex-wrap:wrap;gap:10px;background:#f0f5f8;padding:12px 18px}.mobile-quick{display:flex;flex-wrap:wrap;gap:14px;margin-top:28px}.mobile-quick a{font-size:13px;color:var(--heading)}.split{gap:25px}}
@media(max-width:760px){.split,.split--wide,.split--reverse,.feature-grid,.layout-sidebar,.help-layout{grid-template-columns:minmax(0,1fr)}.layout-sidebar aside{position:static}.help-nav{position:static;order:2}.help-layout>div{order:1}.gallery-grid{gap:15px}.step-list{grid-template-columns:repeat(2,minmax(0,1fr))}.rule-cards{grid-template-columns:minmax(0,1fr)}.rule-cards article:nth-child(n){margin-top:0}.related-links{grid-template-columns:minmax(0,1fr)}.matrix{grid-template-columns:minmax(0,1fr)}.footer-top{flex-direction:column}.feature-grid aside{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.feature-grid aside article+article{margin-top:0}}
@media(max-width:640px){body{font-size:15px;line-height:1.79}.wrap{width:calc(100% - 32px)}.section{margin-block:38px}.home-hero{padding:34px 0 19px}.home-hero h1{font-size:clamp(27px,7vw,32px)}.home-hero .lead{font-size:16px}.page-heading{padding:28px 0}.page-heading h1{font-size:clamp(25px,6.7vw,29px)}.page-lead{font-size:15px}.topic-list,.gallery-grid{grid-template-columns:minmax(0,1fr)}.topic-item{padding:17px 0}.feature-grid aside{grid-template-columns:minmax(0,1fr)}.gallery-grid article:nth-child(n){margin-top:0}.paper,.soft-panel,.mint-panel,.dark-panel,.focus-primary{padding:19px}.step-list{gap:10px}.step-list li{padding:15px}.step-list li p{font-size:13px}.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}.related{padding-top:24px}.register-link{padding:7px 9px;font-size:12px}.brand img{max-width:40vw}.article-section{margin:32px 0 41px}.anchor-nav{gap:7px}.anchor-nav a{font-size:13px;padding:7px 10px}}
@media(max-width:380px){.brand-inner{gap:6px;grid-template-columns:40px minmax(0,1fr) auto}.brand img{max-width:37vw}.brand-fallback{font-size:15px}.register-link{font-size:12px;padding-inline:7px}.step-list{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation-duration:.01ms!important;transition-duration:.01ms!important}}