*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:98px}body{margin:0;background:#F6F8F8;color:#374D58;font:16px/1.82 Arial,"PingFang SC","Microsoft YaHei",sans-serif}a{color:#226D9D;text-underline-offset:3px}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #168E96;outline-offset:3px}img{max-width:100%}.wrap{width:min(1220px,calc(100% - 56px));margin-inline:auto}.site-header{background:#122E3B;color:white;position:relative;z-index:10}.header-inner{max-width:1220px;min-height:74px;margin:auto;padding:0 22px;display:flex;align-items:center;gap:23px}.brand{display:flex;align-items:center;flex-shrink:0;gap:8px;color:#fff;text-decoration:none}.brand-word{font-size:10px;font-weight:700;letter-spacing:.12em;white-space:nowrap}.brand .image-holder{background:transparent;padding:0;border:0;width:auto}.image-holder--logo img{max-height:38px;max-width:110px}.desktop-nav{display:flex;align-items:center;gap:clamp(7px,1vw,18px);flex:1;justify-content:center;min-width:0}.desktop-nav a{white-space:nowrap;color:#E7EFF2;text-decoration:none;font-size:clamp(12px,.99vw,14px);padding:7px 0;border-bottom:2px solid transparent}.desktop-nav a:hover,.desktop-nav .is-current{border-color:#55CED0;color:#fff;font-weight:700}.entry-link{border:1px solid #80C7CE;border-radius:9px;padding:5px 11px;color:#fff;text-decoration:none;white-space:nowrap;font-size:13px}.entry-link:hover{background:#1A4050}.mobile-menu-toggle,.mobile-menu{display:none}.skip-link{position:absolute;top:-80px;left:8px;background:#fff;padding:8px;z-index:30}.skip-link:focus{top:8px}.breadcrumb{font-size:13px;padding-block:17px;display:flex;gap:12px;color:#647981}.breadcrumb a{text-decoration:none}.site-footer{margin-top:70px;background:#0C2632;color:#CDDDE2}.footer-inner{padding-block:38px 25px}.footer-top{display:grid;grid-template-columns:1fr 2fr;gap:38px}.footer-top strong{font-size:20px;color:#fff}.footer-top p{font-size:14px}.footer-top nav{display:flex;flex-wrap:wrap;gap:9px 20px;align-content:start}.footer-top a{color:#E5F5F7;font-size:14px}.footer-note{border-top:1px solid #34525D;padding-top:16px;margin-top:22px;font-size:13px}.site-footer small{font-size:12px}.hero{display:grid;grid-template-columns:minmax(0,1.38fr) minmax(0,1fr);gap:28px;align-items:center;padding:35px 0 27px}.eyebrow{font-size:12px;color:#168E96;font-weight:700;letter-spacing:.15em}.hero h1,h1{font-size:clamp(34px,3vw,42px);line-height:1.29;color:#193946;letter-spacing:-.02em;margin:.35em 0 .52em}.hero p{max-width:690px}.lead{font-size:17px;color:#405D6A}.actions,.related-links{display:flex;gap:12px;flex-wrap:wrap;margin-top:17px}.actions a,.related-links a{display:inline-block;padding:7px 13px;border:1px solid #BED5DD;border-radius:8px;background:#fff;text-decoration:none;font-size:14px}.actions a:hover,.related-links a:hover{border-color:#168E96}.section{margin-top:54px}.section h2,.related h2{font-size:clamp(23px,2.1vw,28px);line-height:1.4;color:#193946;margin:0 0 17px}.section h3{color:#193946;font-size:19px;line-height:1.5;margin:18px 0 7px}.section p,.article p{margin:0 0 16px}.muted{color:#647981}.light-panel{background:#EAF0F2;border:1px solid #D9E3E6;border-radius:11px;padding:24px}.paper{background:#fff;border:1px solid #D9E3E6;border-radius:11px;padding:25px}.grid-two{display:grid;grid-template-columns:1fr 1fr;gap:27px;align-items:start}.grid-wide{display:grid;grid-template-columns:2fr 1fr;gap:30px;align-items:start}.grid-portrait{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(0,.72fr);gap:29px;align-items:center}.split-reverse{direction:rtl}.split-reverse>*{direction:ltr}.topic-groups{display:grid;gap:0;border-top:1px solid #D9E3E6}.topic-row{display:grid;grid-template-columns:1fr 1fr;gap:28px;border-bottom:1px solid #D9E3E6;padding:20px 0}.topic-row article{display:grid;grid-template-columns:40px 1fr;gap:13px}.topic-number{font-size:22px;color:#168E96;font-weight:700}.topic-row h3{margin:0 0 5px;font-size:18px}.topic-row p{margin:0;font-size:14px}.topic-row a{font-weight:700}.steps{counter-reset:step;display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.step{border-top:3px solid #168E96;padding:12px 5px}.step b{display:block;color:#193946;margin-bottom:6px}.step p{font-size:14px}.section-intro{max-width:800px}.page-hero{padding-top:17px;padding-bottom:12px}.page-hero h1{max-width:930px}.page-hero p{max-width:850px}.article-layout{display:grid;grid-template-columns:215px minmax(0,1fr);gap:35px;align-items:start}.toc{background:#EAF0F2;border:1px solid #D9E3E6;border-radius:9px;padding:17px;display:flex;flex-direction:column;gap:7px}.toc strong{color:#193946}.toc a{font-size:14px}.article{max-width:800px;min-width:0}.article section{margin-bottom:36px}.article section h2{font-size:25px;color:#193946;border-bottom:1px solid #D9E3E6;padding-bottom:12px}.article section h3{font-size:19px;color:#193946}.note{border-left:4px solid #168E96;padding:10px 17px;background:#EAF0F2;font-size:14px}.dark-band{background:#1A4050;color:#E9F3F4;padding:28px;border-radius:11px}.dark-band h2,.dark-band h3{color:#fff}.concepts{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.concepts article{background:#fff;border-top:4px solid #168E96;padding:20px;border-radius:7px}.concepts h3{margin-top:0}.wide-table{overflow-x:auto;max-width:100%;border:1px solid #D9E3E6;border-radius:8px;background:#fff}.wide-table table{border-collapse:collapse;width:100%;min-width:580px;font-size:14px}.wide-table caption{caption-side:top;text-align:left;font-weight:700;padding:12px;color:#193946}.wide-table th,.wide-table td{padding:12px 15px;text-align:left;border-bottom:1px solid #D9E3E6;vertical-align:top}.wide-table th{background:#EAF0F2;color:#193946}.image-holder{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;padding:8px;background:#EAF0F2;border-radius:12px}.image-holder img{display:block;width:auto;height:auto;max-width:100%;max-height:var(--image-limit,210px);object-fit:contain;object-position:center}.image-holder--hero{--image-limit:290px}.image-holder--feature{--image-limit:240px}.image-holder--inline{--image-limit:180px}.image-holder--rules{--image-limit:210px}.image-holder--banner{--image-limit:190px}.image-holder--portrait{--image-limit:330px;max-width:310px;margin-inline:auto}.missing-image{border:1px dashed #BFCFD3;background:#EAF0F2;color:#647981;padding:12px;text-align:center;border-radius:8px;font-size:13px}.faq details{border-bottom:1px solid #D9E3E6;background:white;padding:13px 17px}.faq summary{font-weight:700;cursor:pointer;color:#193946}.faq details p{padding:10px 0 0;margin:0;max-width:850px}.related{margin-top:50px;border-top:1px solid #D9E3E6;padding-top:22px}.timeline{border-left:2px solid #168E96;margin-left:10px;padding-left:24px}.timeline article{margin-bottom:23px;position:relative}.timeline article::before{content:'';position:absolute;left:-31px;top:8px;width:12px;height:12px;background:#168E96;border-radius:50%}.timeline h3{margin-top:0}.callout{padding:16px 20px;background:#EAF0F2;border-left:4px solid #168E96;margin:23px 0}.inline-links{display:flex;flex-wrap:wrap;gap:10px;margin:10px 0 25px}.inline-links a{padding:6px 12px;border-radius:30px;border:1px solid #D9E3E6;text-decoration:none;background:#fff;font-size:13px}section[id]{scroll-margin-top:100px}@media(max-width:1150px){.header-inner{gap:12px;padding-inline:16px}.desktop-nav{gap:8px}.brand-word{display:none}}@media(max-width:980px){.wrap{width:calc(100% - 44px)}.header-inner{height:64px;min-height:64px;justify-content:space-between}.mobile-menu-toggle{display:block}.menu-button{border:0;background:transparent;color:#fff;font-size:23px;width:44px;height:44px;cursor:pointer}.desktop-nav{display:none}.brand-word{display:block}.image-holder--logo img{max-height:30px}.mobile-menu:not([hidden]){display:block;position:absolute;top:100%;left:0;right:0;background:#163846;box-shadow:0 12px 22px #122E3B33;padding:15px 22px 23px}.mobile-menu nav{max-width:900px;margin:auto;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.mobile-nav-group{display:flex;flex-direction:column;gap:4px}.mobile-nav-group b{color:#70D1D1;margin-bottom:4px}.mobile-nav-group a{color:#fff;padding:4px 0}.menu-close{color:#fff;background:#1A4050;border:1px solid #89B9C0;border-radius:7px;cursor:pointer;padding:7px}.noscript-nav{background:#1A4050;padding:10px 22px}.noscript-nav nav{display:flex;flex-wrap:wrap;gap:12px}.noscript-nav a{color:#fff}}@media(max-width:760px){.hero,.grid-two,.grid-wide,.grid-portrait,.article-layout,.footer-top{grid-template-columns:1fr}.hero{padding-top:20px}.split-reverse{direction:ltr}.article-layout{gap:20px}.toc{flex-direction:row;flex-wrap:wrap}.steps,.concepts{grid-template-columns:repeat(2,minmax(0,1fr))}.section{margin-top:38px}.footer-top{gap:10px}}@media(max-width:640px){body{font-size:15px;line-height:1.78}.wrap{width:calc(100% - 32px)}h1,.hero h1{font-size:clamp(26px,7vw,30px)}.section h2{font-size:22px}.hero{gap:12px}.topic-row{grid-template-columns:1fr;gap:15px}.paper,.light-panel{padding:17px}.steps,.concepts{grid-template-columns:1fr}.mobile-menu nav{grid-template-columns:1fr 1fr}.image-holder--hero{--image-limit:195px}.image-holder--feature{--image-limit:180px}.image-holder--inline{--image-limit:140px}.image-holder--rules{--image-limit:165px}.image-holder--banner{--image-limit:125px}.image-holder--portrait{--image-limit:275px;max-width:240px}.image-holder--logo img{max-height:30px}.brand-word{font-size:9px}.entry-link{padding:5px 7px}.site-footer{margin-top:45px}}@media(max-width:390px){.brand-word{display:none}.mobile-menu nav{grid-template-columns:1fr}.header-inner{padding-inline:12px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}