:root{--page:#F6FAFC;--white:#fff;--soft:#EAF6FA;--soft2:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--title:#183A56;--body:#31485D;--muted:#687D8E;--border:#DCE9F0;--footer:#123653;--font:Arial,"PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:30px}body{margin:0;color:var(--body);background:var(--page);font:16px/1.8 var(--font)}body.drawer-active{overflow:hidden}a{color:var(--navy);text-decoration-thickness:1px;text-underline-offset:4px}a:hover{color:var(--blue)}:focus-visible{outline:3px solid var(--sky);outline-offset:4px}button{font:inherit;cursor:pointer}.shell{width:min(1180px,calc(100% - 56px));margin-inline:auto}.site-header{position:relative;z-index:20;background:#fff;box-shadow:0 1px 0 var(--border)}.topbar{height:72px;display:flex;align-items:center;gap:26px}.brand{display:inline-flex;align-items:center;flex:0 0 auto;max-width:210px;min-width:0;text-decoration:none}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:190px;object-fit:contain}.brand-type{font-weight:900;letter-spacing:.02em;font-size:22px;color:var(--navy);white-space:nowrap}.brand-type b{color:#17b5c9}.brand-tagline{margin-inline:auto;color:var(--muted);font-size:14px;letter-spacing:.16em}.entry-btn,.button-primary{display:inline-flex;gap:10px;align-items:center;justify-content:center;background:var(--navy);color:#fff!important;border-radius:9px;font-weight:700;text-decoration:none;padding:9px 19px;white-space:nowrap;min-height:42px}.entry-btn:hover,.button-primary:hover{background:#0b6597}.desktop-nav{background:var(--navy)}.nav-row{display:flex;align-items:stretch;justify-content:space-between;gap:6px;min-height:48px}.nav-row a{color:#e7f6ff;text-decoration:none;padding:11px 12px 9px;border-bottom:3px solid transparent;font-size:14px;white-space:nowrap}.nav-row a:hover,.nav-row a[aria-current]{color:#fff;border-bottom-color:var(--cyan);background:#ffffff15}.menu-toggle{display:none}.drawer-overlay,.mobile-drawer,.bottom-nav{display:none}.skip-link{position:absolute;left:10px;top:-80px;background:#fff;padding:10px;z-index:99}.skip-link:focus{top:8px}.section{margin-block:58px}.section-head{margin-bottom:24px}.eyebrow{display:block;color:#177e9a;font-size:12px;font-weight:800;letter-spacing:.17em;text-transform:uppercase;margin-bottom:8px}.section h2,h2{font-size:clamp(22px,2.4vw,27px);line-height:1.4;color:var(--title);margin:0 0 15px}.section-head h2{margin:0}.section-head p{margin:10px 0 0;max-width:780px;color:var(--muted)}h1{font-size:clamp(32px,3.5vw,40px);line-height:1.34;color:var(--title);letter-spacing:-.035em;margin:15px 0 22px}h3{font-size:19px;line-height:1.4;color:var(--title);margin:0 0 12px}p{margin:0 0 16px}strong{color:var(--title)}.muted{color:var(--muted)}.hero{display:grid;grid-template-columns:56fr 44fr;gap:40px;align-items:center;padding:46px 0 30px}.hero-copy{max-width:630px}.hero p{max-width:600px}.hero-actions{display:flex;gap:18px;flex-wrap:wrap;align-items:center;margin-top:28px}.text-link{font-weight:700}.media{width:100%;min-width:0;display:flex;align-items:center;justify-content:center;overflow:hidden;border-radius:14px;background:var(--soft);position:relative}.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--portrait{max-width:420px;margin-inline:auto}.media--wide{height:auto;aspect-ratio:3/1}.media-placeholder{width:34%;height:38%;border:2px solid #c8e7ef;border-radius:12px;opacity:.75;background:linear-gradient(135deg,#eaf6fa,#dfeff5)}.quick-reading{border-block:1px solid var(--border);background:#fff}.quick-reading .shell{display:flex;flex-wrap:wrap;gap:10px 40px;padding-block:15px}.quick-reading div{display:flex;flex-wrap:wrap;gap:12px;align-items:center}.quick-reading b{font-size:13px;color:var(--title)}.quick-reading a{font-size:13px;text-decoration:none}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:23px 22px;text-decoration:none;display:block;min-height:160px;transition:transform .2s,border .2s}.topic-card:hover{transform:translateY(-2px);border-color:var(--sky)}.topic-card small{color:var(--blue);font-weight:700}.topic-card strong{display:block;margin:9px 0 6px;font-size:18px}.topic-card span{display:block;font-size:14px;color:var(--muted);line-height:1.7}.editorial-grid{display:grid;grid-template-columns:2fr 1fr;gap:20px}.feature-story{background:var(--soft);border-radius:16px;padding:32px}.feature-story h3{font-size:24px}.story-stack{display:grid;gap:20px}.mini-story{background:#fff;border:1px solid var(--border);padding:25px;border-radius:14px}.mini-story p{font-size:15px}.split{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}.split--text-wide{grid-template-columns:1.2fr .8fr}.split p{max-width:650px}.tinted-section{padding:36px;border-radius:18px;background:var(--soft)}.knowledge-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.knowledge-box{background:#fff;border:1px solid var(--border);border-top:4px solid var(--cyan);border-radius:10px;padding:24px}.knowledge-box .number{font-weight:900;color:var(--blue);font-size:13px}.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;counter-reset:step}.step{border-left:2px solid var(--cyan);padding:4px 18px 8px;background:#fff}.step::before{counter-increment:step;content:'0' counter(step);display:block;color:var(--blue);font-weight:900;font-size:13px;margin-bottom:7px}.reading-note{padding:24px;border-left:4px solid var(--cyan);background:#fff;color:var(--muted);font-size:14px}.page-heading{padding:42px 0 20px;max-width:850px}.page-heading h1{font-size:clamp(30px,3.1vw,36px)}.page-heading .lead{font-size:17px;line-height:1.85}.article-section{margin-block:40px}.article-section>p{max-width:790px}.article-section h2{margin-bottom:20px}.article-section h3{margin-top:20px}.content-card{padding:27px;background:#fff;border:1px solid var(--border);border-radius:13px}.content-card p:last-child,.knowledge-box p:last-child,.mini-story p:last-child{margin-bottom:0}.cards-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.cards-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.comparison{width:100%;border-collapse:collapse;background:#fff;font-size:15px}.table-scroll{max-width:100%;overflow-x:auto;border:1px solid var(--border);border-radius:12px}.comparison th,.comparison td{text-align:left;vertical-align:top;border-bottom:1px solid var(--border);padding:15px 18px;min-width:135px}.comparison th{color:var(--title);background:var(--soft);font-weight:700}.comparison tr:last-child td{border-bottom:0}.timeline{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.timeline article{padding:25px;background:#fff;border-top:4px solid var(--cyan)}.timeline b{display:block;color:var(--blue);margin-bottom:7px}.article-layout{display:grid;grid-template-columns:minmax(0,760px) minmax(0,240px);gap:45px;align-items:start}.article-layout .article-section:first-child{margin-top:0}.article-layout aside{position:sticky;top:22px;background:#eaf6fa;border:1px solid var(--border);padding:22px;border-radius:12px}.article-layout aside dl{margin:0}.article-layout aside dt{font-weight:700;color:var(--title);margin-top:15px}.article-layout aside dd{margin:0;font-size:14px}.section-nav{display:flex;flex-wrap:wrap;gap:10px;margin:10px 0 24px}.section-nav a{display:inline-block;padding:7px 12px;border:1px solid var(--border);border-radius:7px;background:#fff;text-decoration:none;font-size:14px}.visual-gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:23px}.gallery-item{padding:15px 15px 22px;background:#fff;border:1px solid var(--border);border-radius:13px}.gallery-item h3,.gallery-item p{margin-inline:6px}.gallery-item h3{margin-top:15px}.gallery-item p{font-size:14px;color:var(--muted)}.rule-block{margin-block:44px;padding-bottom:25px;border-bottom:1px solid var(--border)}.faq-list{display:grid;gap:10px}.faq-list details{background:#fff;border:1px solid var(--border);border-radius:9px;padding:0 18px}.faq-list summary{cursor:pointer;color:var(--title);font-weight:700;padding:14px 3px}.faq-list details p{border-top:1px solid var(--border);padding-top:12px;font-size:15px}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.related-link{position:relative;display:block;text-decoration:none;background:#fff;border:1px solid var(--border);border-radius:10px;padding:21px 35px 22px 20px}.related-link strong,.related-link span{display:block}.related-link span{font-size:13px;color:var(--muted);margin-top:7px}.related-link .arrow{position:absolute;right:18px;top:16px;color:var(--blue);font-size:20px}.site-footer{background:var(--footer);color:#eaf7ff;margin-top:75px}.footer-main{display:grid;grid-template-columns:1.1fr 1fr;gap:40px;padding-block:46px}.footer-main strong{color:#fff;font-size:20px}.footer-main strong span{font-size:12px;color:#b6dbe9;margin-left:8px;letter-spacing:.1em}.footer-main p{margin:12px 0}.footer-disclaimer{color:#c7e3f0;font-size:13px;max-width:550px}.footer-main nav{display:grid;grid-template-columns:repeat(3,1fr);gap:10px 20px;align-content:start}.site-footer a{color:#eaf7ff;font-size:14px}.footer-bottom{padding:17px 0;border-top:1px solid #ffffff27;display:flex;justify-content:space-between;gap:15px;flex-wrap:wrap;font-size:12px;color:#b6dbe9}.back-to-top{position:fixed;right:22px;bottom:24px;border:0;background:var(--navy);color:#fff;border-radius:10px;width:43px;height:43px;opacity:0;visibility:hidden;transition:opacity .2s;z-index:19}.back-to-top.is-visible{opacity:1;visibility:visible}
@media(max-width:980px){.shell{width:min(100% - 44px,1180px)}.topbar{height:64px;justify-content:space-between;gap:10px}.menu-toggle{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;background:none;border:0;width:40px;height:40px;flex-shrink:0}.menu-toggle span{width:20px;height:2px;background:var(--navy);border-radius:2px}.brand{margin-inline:auto}.brand img{max-height:30px;max-width:140px}.brand-type{font-size:16px}.brand-tagline,.desktop-nav{display:none}.entry-btn{min-height:40px;padding:7px 10px;font-size:13px}.drawer-overlay{display:block;position:fixed;inset:0;background:#0e284b88;z-index:29;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer-overlay.is-open{opacity:1;visibility:visible;pointer-events:auto}.mobile-drawer{display:block;position:fixed;inset:0 auto 0 0;width:min(86vw,344px);max-height:100dvh;overflow:auto;overscroll-behavior:contain;background:#fff;z-index:30;transform:translateX(-103%);visibility:hidden;transition:transform .25s,visibility .25s;padding:24px}.mobile-drawer.is-open{transform:translateX(0);visibility:visible}.drawer-top{display:flex;align-items:center;justify-content:space-between;color:var(--title);font-size:19px}.drawer-close{background:var(--soft);border:0;border-radius:7px;font-size:26px;width:40px;height:40px;color:var(--navy)}.drawer-intro{font-size:13px;color:var(--muted);margin-top:10px}.drawer-group{display:grid;gap:3px;margin-top:24px}.drawer-group>span{font-weight:700;color:var(--muted);font-size:12px;padding-bottom:9px;border-bottom:1px solid var(--border)}.drawer-group a{display:block;padding:10px 5px;text-decoration:none;color:var(--title)}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.article-layout{grid-template-columns:minmax(0,1fr) 210px;gap:24px}}
@media(max-width:760px){.hero,.split,.split--text-wide,.editorial-grid,.article-layout,.footer-main{grid-template-columns:1fr}.hero{gap:20px;padding-top:28px}.hero-copy{order:1}.hero>.media{order:2}.article-layout aside{position:static}.cards-3,.knowledge-grid,.timeline{grid-template-columns:1fr 1fr}.visual-gallery{grid-template-columns:1fr}.steps{grid-template-columns:1fr 1fr}.related-grid{grid-template-columns:1fr}.footer-main nav{grid-template-columns:repeat(3,1fr)}}
@media(max-width:640px){body{font-size:15px}.shell{width:calc(100% - 32px)}.section{margin-block:35px}.section h2,h2{font-size:22px}h1{font-size:29px}.page-heading h1{font-size:27px}.page-heading{padding-top:27px}.page-heading .lead{font-size:15px}.hero h1{font-size:29px}.hero-actions{gap:15px}.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{height:auto}.quick-reading .shell{gap:8px 20px}.quick-reading div{gap:9px}.topic-grid{grid-template-columns:1fr 1fr;gap:10px}.topic-card{padding:16px;min-height:0}.topic-card strong{font-size:16px}.topic-card span{font-size:13px}.feature-story{padding:23px}.feature-story h3{font-size:21px}.cards-2,.cards-3,.knowledge-grid,.timeline,.steps{grid-template-columns:1fr}.tinted-section{padding:22px 17px}.article-section{margin-block:32px}.content-card{padding:20px}.site-footer{margin-top:42px;padding-bottom:68px}.footer-main{padding-block:32px;gap:24px}.footer-main nav{grid-template-columns:repeat(2,1fr)}.bottom-nav{position:fixed;inset:auto 0 0;display:grid;grid-template-columns:repeat(4,1fr);padding-bottom:env(safe-area-inset-bottom);height:calc(58px + env(safe-area-inset-bottom));background:#fff;border-top:1px solid var(--border);z-index:18;box-shadow:0 -2px 15px #1236530d}.bottom-nav a{text-decoration:none;text-align:center;font-size:13px;font-weight:700;padding:14px 0;color:var(--navy)}.bottom-nav a[aria-current]{color:var(--blue);border-top:3px solid var(--cyan);padding-top:11px}.back-to-top{bottom:calc(72px + env(safe-area-inset-bottom));right:14px}.footer-bottom{font-size:11px}.brand img{max-width:110px}.entry-btn{font-size:12px;padding-inline:8px}}
@media(max-width:380px){.brand-type{font-size:13px}.entry-btn span{display:none}.topic-grid{grid-template-columns:1fr}.topbar{gap:5px}}@media(max-height:480px) and (max-width:640px){.bottom-nav{position:static;height:auto;padding-bottom:0}.site-footer{padding-bottom:0}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}