:root{--bg:#F4F7FA;--white:#fff;--soft:#EAF1F6;--mint:#E9F8F8;--navy:#102E46;--navy2:#163C57;--teal:#13B8C5;--blue:#237BD3;--head:#18364B;--text:#344C60;--muted:#64798A;--border:#DCE6ED;--footer:#0B2539}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:20px}body{margin:0;background:var(--bg);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text)}a{color:var(--blue);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}h1,h2,h3{color:var(--head);line-height:1.38;margin:0 0 .65em;font-weight:750}h1{font-size:clamp(2rem,3.1vw,2.35rem)}h2{font-size:clamp(1.45rem,2vw,1.7rem)}h3{font-size:1.2rem}p{margin:.65em 0 1.15em}ul,ol{padding-left:1.4em}li+li{margin-top:.45em}.container{width:min(100% - 56px,1200px);margin-inline:auto}.reading{max-width:790px}.section{margin-block:64px}.section-header{margin-bottom:22px}.eyebrow{font-size:.82rem;letter-spacing:.12em;text-transform:uppercase;color:#087c87;font-weight:700}.lead{font-size:1.12rem;max-width:800px;color:#405b6d}.subtle{color:var(--muted)}.skip-link{position:absolute;z-index:200;top:-80px;left:12px;background:#fff;padding:10px}.skip-link:focus{top:10px}.site-header{background:var(--navy);color:#fff}.brand-bar{background:#fff}.brand-inner{height:72px;display:flex;align-items:center;gap:18px}.brand{display:flex;align-items:center;min-width:0;flex-shrink:0;color:var(--navy);font-size:22px;font-weight:800}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:min(230px,34vw);object-fit:contain}.brand small,.footer-brand small{display:block;font-size:10px;letter-spacing:.14em}.brand-note{color:var(--muted);font-size:13px;border-left:1px solid var(--border);padding-left:17px}.register-link{margin-left:auto;display:inline-flex;align-items:center;justify-content:center;background:var(--navy);color:#fff;border-radius:10px;padding:6px 23px;font-weight:700;white-space:nowrap;min-height:42px}.register-link:hover{color:#fff;background:var(--navy2);text-decoration:none}.desktop-nav{background:var(--navy)}.channel-list{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));align-items:stretch}.channel-list a{min-width:0;position:relative;color:#dcecf5;font-size:14px;font-weight:600;text-align:center;padding:12px 4px;white-space:nowrap}.channel-list a:hover,.channel-list a[aria-current]{color:#fff;text-decoration:none}.channel-list a[aria-current]::after{content:'';position:absolute;bottom:0;left:25%;right:25%;height:3px;background:var(--teal)}.menu-toggle{display:none}.menu-overlay{position:fixed;inset:0;background:rgba(4,18,31,.56);z-index:100;visibility:hidden;pointer-events:none}.menu-overlay.is-visible{visibility:visible;pointer-events:auto}.menu-overlay[hidden]{display:none}.mobile-drawer{position:fixed;top:0;bottom:0;left:0;width:min(86vw,340px);background:white;z-index:110;transform:translateX(-102%);visibility:hidden;transition:transform .24s ease,visibility .24s;overflow-y:auto;box-shadow:12px 0 35px #142f4430}.mobile-drawer.is-open{transform:translateX(0);visibility:visible}.drawer-top{display:flex;align-items:center;justify-content:space-between;background:var(--navy);color:#fff;padding:15px 19px;font-weight:700}.menu-close{font-size:30px;color:#fff;border:0;background:transparent;cursor:pointer;width:42px;height:42px}.mobile-drawer nav{display:flex;flex-direction:column;padding:8px 18px 30px}.mobile-drawer nav a{padding:11px 12px;border-bottom:1px solid var(--border);color:var(--head)}.drawer-label{font-size:12px;color:var(--muted);font-weight:700;margin:16px 12px 0}body.menu-open{overflow:hidden}.nojs-nav{display:none}.breadcrumbs{font-size:13px;color:var(--muted);margin:24px 0}.breadcrumbs a{color:var(--muted)}.page-intro{padding:44px 0 27px;border-bottom:1px solid var(--border)}.page-intro p{max-width:790px}.toc{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0 10px}.toc a{display:inline-block;background:var(--white);border:1px solid var(--border);border-radius:999px;padding:5px 18px;color:var(--head);font-size:14px}.cover{display:grid;grid-template-columns:52fr 48fr;gap:32px;align-items:center;padding:58px 0 48px}.cover h1{font-size:clamp(2rem,3.4vw,2.75rem)}.cover p{max-width:590px}.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}.btn{display:inline-flex;background:var(--navy);color:#fff;border-radius:9px;padding:10px 22px;align-items:center;font-weight:700}.btn:hover{background:var(--navy2);color:white;text-decoration:none}.btn-outline{background:transparent;border:1px solid var(--blue);color:var(--blue)}.btn-outline:hover{color:#fff;background:var(--blue)}.media-frame{margin:0;display:flex;justify-content:center;align-items:center;min-width:0;width:100%;padding:10px;background:var(--soft);border:1px solid var(--border);border-radius:14px;--media-limit:220px}.media-frame img{display:block;max-width:100%;max-height:var(--media-limit);width:auto;height:auto;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--banner{--media-limit:210px}.media-frame--mobile{--media-limit:350px;max-width:320px}.media-placeholder{display:flex;align-items:center;justify-content:center;min-height:110px;width:100%;border:1px dashed #b6cfda;border-radius:9px;color:var(--muted);font-size:14px}.media-frame--hero .media-placeholder{min-height:220px}.media-frame--mobile .media-placeholder{min-height:220px}.editorial-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:42px}.index-link{padding:19px 0;border-top:1px solid var(--border)}.index-link h3{margin-bottom:5px}.index-link p{margin:0 0 7px;font-size:15px}.feature-layout{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:22px}.feature-large{padding:30px;background:var(--navy);border-radius:14px;color:#e4f2f6}.feature-large h3{color:white}.feature-large a{color:#70dfe7}.feature-small{padding:20px 0;border-bottom:1px solid var(--border)}.split{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:30px;align-items:center}.split--wide{grid-template-columns:1.2fr .8fr}.split--reverse{grid-template-columns:.85fr 1.15fr}.band{padding:32px;background:var(--white);border:1px solid var(--border);border-radius:14px}.mint-band{background:var(--mint)}.dark-band{background:var(--navy2);color:#f1f8fc}.dark-band h2,.dark-band h3{color:#fff}.dark-band a{color:#8be7ef}.steps{counter-reset:step;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:15px;list-style:none;padding:0}.steps li{position:relative;padding:20px;background:#fff;border-top:3px solid var(--teal);border-radius:4px 4px 12px 12px}.steps li::before{counter-increment:step;content:'0' counter(step);display:block;font-size:13px;color:#108795;font-weight:800;letter-spacing:.1em}.steps h3{font-size:17px;margin:7px 0}.steps p{font-size:14px;margin:0}.article-section{margin:48px 0;max-width:790px}.article-section p{line-height:1.85}.chapter{margin:50px 0;padding-top:25px;border-top:1px solid var(--border)}.chapter--alt{background:#fff;border:1px solid var(--border);border-radius:14px;padding:26px}.chapter-layout{display:grid;grid-template-columns:minmax(0,2.2fr) minmax(0,1fr);gap:30px;align-items:start}.side-note{padding:23px;background:var(--mint);border-left:3px solid var(--teal);font-size:14px}.side-note h3{font-size:17px}.list-plain{padding-left:18px}.table-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--border);border-radius:12px;background:white}.comparison{width:100%;border-collapse:collapse;min-width:560px;font-size:15px}.comparison caption{text-align:left;padding:12px 16px;color:var(--head);font-weight:bold}.comparison th,.comparison td{text-align:left;vertical-align:top;padding:13px 15px;border-bottom:1px solid var(--border)}.comparison th{background:#eaf1f6;color:var(--head)}.comparison tr:last-child td{border-bottom:0}.timeline{list-style:none;border-left:2px solid var(--teal);padding-left:22px}.timeline li{position:relative;margin:0 0 25px}.timeline li:before{content:'';position:absolute;top:9px;left:-29px;border-radius:50%;width:11px;height:11px;background:var(--teal)}.tag{font-size:12px;letter-spacing:.1em;color:#0b8390;font-weight:700;text-transform:uppercase}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.matrix article{background:#fff;border:1px solid var(--border);padding:22px;border-radius:12px}.gallery{display:grid;grid-template-columns:1fr 1fr;gap:30px;align-items:start}.gallery article:nth-child(even){margin-top:48px}.gallery h3{margin-top:12px}.faq-list{border-top:1px solid var(--border)}.faq-list details{border-bottom:1px solid var(--border);padding:16px 0}.faq-list summary{cursor:pointer;color:var(--head);font-weight:700;padding-right:24px}.faq-list p{margin:10px 0 2px}.related{padding:28px 0;border-top:2px solid var(--navy);margin:55px 0}.related-list{display:flex;flex-wrap:wrap;gap:12px}.related-list a{background:white;border:1px solid var(--border);border-radius:9px;padding:9px 17px}.service-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:38px}.service-nav{position:sticky;top:16px;align-self:start;padding:20px;background:white;border:1px solid var(--border);border-radius:12px}.service-nav a{display:block;padding:6px 0}.service-main section{margin-bottom:44px}.mobile-quick{display:none}.site-footer{background:var(--footer);color:#dcecf5;padding-top:46px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:45px}.site-footer h2{font-size:17px;color:#fff}.site-footer a{color:#dcecf5}.footer-grid>div:not(:first-child) a{display:block;margin:8px 0}.footer-brand>a{font-weight:bold;font-size:22px}.footer-brand p{font-size:14px;color:#c8d8e1}.footer-bottom{border-top:1px solid #355064;margin-top:36px;padding:18px 0;color:#b6cbd7;font-size:13px}.back-top{position:fixed;right:18px;bottom:20px;border:0;border-radius:50%;height:42px;width:42px;background:var(--navy);color:white;cursor:pointer;font-size:21px}.back-top[hidden]{display:none}
@media(max-width:1024px){.container{width:min(100% - 44px,1200px)}.section{margin-block:48px}.cover{gap:20px}.brand-note{font-size:12px}.channel-list a{font-size:13px}}
@media(max-width:920px){.site-header{position:relative}.brand-inner{height:62px;display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:8px}.menu-toggle{width:40px;height:40px;display:flex;align-items:center;justify-content:center;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer}.menu-toggle span{width:21px;height:2px;background:var(--navy);display:block}.brand{justify-self:center}.brand img{max-height:30px;max-width:min(220px,37vw)}.brand-fallback{font-size:17px;text-align:center}.brand-fallback small{font-size:8px}.brand-note,.desktop-nav{display:none}.register-link{margin:0;padding:6px 11px;min-height:39px;font-size:12px}.nojs-nav{display:flex;gap:11px;flex-wrap:wrap;padding:10px 0}.nojs-nav a{font-size:13px}.mobile-quick{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;padding:22px 0}.mobile-quick a{font-size:14px}.footer-grid{gap:22px}}
@media(max-width:760px){.cover,.split,.split--wide,.split--reverse,.feature-layout,.chapter-layout,.service-layout{grid-template-columns:1fr}.cover{padding:32px 0 18px}.cover .media-frame{max-width:100%}.editorial-grid,.gallery{grid-template-columns:1fr}.gallery article:nth-child(even){margin-top:0}.matrix{grid-template-columns:1fr}.steps{grid-template-columns:repeat(2,minmax(0,1fr))}.service-nav{position:static;order:2}.service-main{order:1}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.page-intro{padding:24px 0}.section{margin-block:38px}}
@media(max-width:640px){body{font-size:15px}.container{width:calc(100% - 32px)}h1{font-size:clamp(25px,6vw,29px)}.cover h1{font-size:clamp(27px,7vw,32px)}h2{font-size:clamp(20px,5vw,23px)}h3{font-size:17px}.lead{font-size:16px}.section{margin-block:34px}.media-frame{padding:7px}.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;margin-inline:auto}.media-frame--banner{--media-limit:135px}.band{padding:18px}.feature-large{padding:22px}.steps{gap:9px}.steps li{padding:14px}.footer-grid{grid-template-columns:1fr;gap:12px}.footer-brand{grid-column:auto}.register-link{padding:6px 9px}.brand img{max-width:39vw}.related-list{flex-direction:column}.related-list a{display:block}}
@media(max-width:380px){.brand img{max-width:35vw}.register-link{font-size:11px;padding:4px 7px}.brand-inner{gap:4px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}