:root{--bg:#f5fbff;--surface:#fff;--pale:#eaf7fc;--mint:#dff5fb;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--deep:#174b78;--title:#173b60;--text:#2d4359;--muted:#687f93;--border:#dcebf3;--radius:18px;--shadow:0 12px 40px rgba(23,75,120,.065)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:88px}body{margin:0;background:var(--bg);color:var(--text);font-family:Arial,"PingFang SC","Microsoft YaHei",sans-serif;font-size:16px;line-height:1.8}button,input{font:inherit}button{cursor:pointer}a{color:var(--deep);text-decoration:none}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}.container{width:min(1160px,calc(100% - 48px));margin-inline:auto}.skip-link{position:absolute;left:12px;top:-100px;z-index:1100;background:#fff;padding:8px}.skip-link:focus{top:8px}.site-header{height:72px;background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}.header-inner{height:100%;display:flex;align-items:center;gap:22px}.brand{display:flex;align-items:center;gap:9px;flex-shrink:0;min-width:172px}.brand img{display:block;width:auto;max-width:180px;height:auto;max-height:38px;object-fit:contain}.brand-mark{width:38px;height:38px;border-radius:12px;color:#fff;display:grid;place-items:center;font-weight:900;font-size:23px;background:linear-gradient(125deg,var(--cyan),var(--blue));transform:skew(-5deg)}.brand-words{display:flex;flex-direction:column;line-height:1.2;color:var(--title)}.brand-words strong{font-size:19px;letter-spacing:1px}.brand-words small{font-size:10px;color:var(--blue);letter-spacing:1.5px}.desktop-nav{display:flex;align-items:center;justify-content:center;gap:clamp(8px,1.2vw,19px);flex:1}.desktop-nav a{font-size:14px;font-weight:600;white-space:nowrap;display:flex;height:72px;align-items:center;position:relative}.desktop-nav a.active{color:var(--blue)}.desktop-nav a.active:after{content:"";position:absolute;bottom:0;left:10%;width:80%;height:3px;background:var(--cyan);border-radius:4px 4px 0 0}.main-btn{display:inline-flex;align-items:center;justify-content:center;min-width:82px;height:42px;padding:0 20px;border-radius:999px;background:linear-gradient(110deg,#25c8d1,#25b6e8,#1787db);color:#fff;font-weight:700;white-space:nowrap;font-size:14px}.main-btn:hover{color:#fff;filter:brightness(.95)}.menu-toggle{display:none;border:0;background:transparent;width:42px;height:42px;flex-direction:column;align-items:center;justify-content:center;gap:5px;padding:9px}.menu-toggle span{height:2px;width:22px;background:var(--title);border-radius:2px}.menu-overlay{position:fixed;inset:0;background:rgba(8,31,51,.52);z-index:190;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.mobile-menu{position:fixed;top:0;bottom:0;left:0;width:min(86vw,340px);overflow:auto;background:#fff;z-index:200;box-shadow:8px 0 35px #12365322;transform:translateX(-105%);visibility:hidden;transition:transform .25s,visibility .25s}.menu-open{overflow:hidden}.menu-open .mobile-menu{transform:translateX(0);visibility:visible}.menu-open .menu-overlay{visibility:visible;opacity:1;pointer-events:auto}.drawer-top{display:flex;align-items:center;justify-content:space-between;padding:18px 20px;background:var(--pale);border-bottom:1px solid var(--border)}.drawer-title{font-weight:800;font-size:19px;color:var(--title)}.drawer-title small{display:block;font-size:11px;color:var(--muted);font-weight:400}.drawer-close{border:0;background:#fff;width:38px;height:38px;border-radius:10px;font-size:29px;line-height:1;color:var(--title)}.drawer-group{padding:12px 20px;border-bottom:1px solid var(--border)}.drawer-group>span{font-weight:700;color:var(--blue);font-size:13px;display:block;margin-bottom:5px}.drawer-group a{display:block;padding:7px 0;font-size:15px}.site-footer{background:#123653;color:#eaf7ff;margin-top:65px}.footer-inner{display:grid;grid-template-columns:2.1fr 1fr 1fr;gap:48px;padding:47px 0 36px}.footer-brand strong{display:block;font-size:24px;color:#fff}.footer-brand small{display:block;font-size:11px;letter-spacing:2px;color:#a6e6f1}.footer-brand p{max-width:430px;font-size:14px;color:#c5d9e5}.footer-links h2{font-size:16px;margin:0 0 10px;color:#fff}.footer-links a{display:block;font-size:14px;color:#c5d9e5;padding:3px 0}.footer-links a:hover{color:#fff}.footer-bottom{border-top:1px solid #ffffff20;padding:18px 0 25px;font-size:12px;color:#b9d2e1}.footer-bottom p{margin:4px 0}.back-top{position:fixed;right:22px;bottom:25px;opacity:0;pointer-events:none;width:42px;height:42px;border-radius:50%;border:0;color:#fff;background:var(--blue);box-shadow:var(--shadow);transition:opacity .2s}.back-top.visible{opacity:1;pointer-events:auto}.mobile-bottom{display:none}
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.lead{max-width:580px}.hero-actions{display:flex;gap:11px;flex-wrap:wrap;margin-top:25px}.outline-btn{display:inline-flex;align-items:center;justify-content:center;min-height:42px;border:1px solid #a5d6ec;border-radius:999px;padding:0 19px;color:var(--deep);font-weight:700;font-size:14px;background:#ffffffc7}.outline-btn:hover{border-color:var(--blue)}.media{display:flex;justify-content:center;align-items:center;width:100%;overflow:hidden;background:var(--pale);border:1px solid var(--border);border-radius:14px}.media--hero{height:315px}.media--wide{height:220px}.media--card{height:160px}.media--portrait{height:340px;max-width:360px;margin-inline:auto}.media--banner{height:250px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media-placeholder{height:100%;width:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;padding:20px;text-align:center;color:#5b8ca5;font-size:13px;background:radial-gradient(circle at 22% 18%,#fff 0,transparent 40%),linear-gradient(145deg,#dff5fb,#cce9f6)}.placeholder-art{width:min(140px,38%);aspect-ratio:1.4;border-radius:40% 55% 45% 50%;background:linear-gradient(135deg,#25c8d148,#1787db65);box-shadow:30px 18px 0 -9px #ffffff8f, -25px -20px 0 -17px #25b6e87a;transform:rotate(-10deg)}.feature-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:19px}.feature-card{padding:24px;background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);transition:transform .2s}.feature-card:hover{transform:translateY(-3px)}.feature-card h3{margin-top:13px}.feature-card p{font-size:14px;color:var(--muted);margin:0 0 12px}.mini-label{font-size:12px;font-weight:700;color:#1595a6}.feature-card>a{font-size:14px;font-weight:700;color:var(--blue)}.split{display:grid;grid-template-columns:1fr 1fr;gap:32px;align-items:center}.panel{background:#fff;border:1px solid var(--border);padding:30px;border-radius:var(--radius);box-shadow:var(--shadow)}.editorial-list{display:grid;gap:13px}.editorial-item{display:flex;gap:17px;padding:16px 0;border-bottom:1px solid var(--border)}.editorial-item:last-child{border:0}.editorial-item b{color:#36b7d0;font-size:23px;line-height:1}.editorial-item h3{font-size:17px;margin:0 0 4px}.editorial-item p{font-size:14px;color:var(--muted);margin:0}.topic-strip{background:#e5f5fb;border-block:1px solid var(--border)}.topic-tags{display:flex;flex-wrap:wrap;gap:12px}.topic-tags a{background:#fff;border:1px solid #cee8f2;border-radius:999px;padding:8px 16px;font-size:14px;font-weight:600}.intro-band{padding:48px 0 30px;background:linear-gradient(120deg,#e5f7fc,#f5fbff)}.intro-band .container{display:grid;grid-template-columns:1fr .67fr;gap:60px;align-items:center}.intro-band h1{font-size:33px}.intro-band .lead{max-width:720px}.article-wrap{padding:36px 0 15px}.article-grid{display:grid;grid-template-columns:minmax(0,790px) 270px;gap:45px;align-items:start}.article{font-size:16px;line-height:1.84}.article>section{margin:0 0 42px}.article p{margin-bottom:17px}.article ul,.article ol{padding-left:22px;margin:14px 0 22px}.article li{margin:6px 0}.article h2{margin:0 0 17px;padding-top:3px}.article h3{margin-top:20px}.sidebar{position:sticky;top:102px}.toc{background:#fff;border:1px solid var(--border);border-radius:14px;padding:21px}.toc h2{font-size:17px}.toc a{display:block;font-size:14px;padding:7px 0;border-bottom:1px solid var(--border)}.toc a:last-child{border:0}.pullquote{border-left:4px solid var(--cyan);margin:23px 0;background:#e9f8fc;padding:19px 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a{display:flex;justify-content:space-between;gap:8px;padding:14px 17px;border:1px solid var(--border);border-radius:12px;background:#fff;font-size:14px;font-weight:600}.related-links span{color:var(--sky)}.numbered{counter-reset:steps}.numbered>div{position:relative;padding:2px 0 17px 55px;margin:0 0 17px;border-bottom:1px solid var(--border);counter-increment:steps}.numbered>div:before{content:counter(steps,decimal-leading-zero);position:absolute;left:0;top:0;font-size:25px;font-weight:800;color:#27b2d3}.numbered h3{margin:0 0 5px}.numbered p{margin:0}.faq details{border:1px solid var(--border);border-radius:12px;background:#fff;margin-bottom:10px;padding:0 18px}.faq summary{cursor:pointer;padding:15px 0;font-weight:700;color:var(--title)}.faq details p{padding:0 0 14px;margin:0;color:var(--text)}.insight-row{display:grid;grid-template-columns:1.2fr 1fr;gap:26px;align-items:center;margin:0 0 33px}.insight-row:nth-child(even){grid-template-columns:1fr 1.2fr}.insight-row:nth-child(even) .media{order:2}.kicker{display:inline-block;background:#e2f6fb;color:#1498b0;padding:4px 10px;border-radius:5px;font-size:12px;font-weight:700;margin-bottom:10px}.card-list{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}.mobile-read{background:linear-gradient(100deg,#e4f6fd,#fff);border:1px solid var(--border);border-radius:18px;padding:27px}.quick-index{display:grid;grid-template-columns:repeat(4,1fr);gap:13px}.quick-index a{padding:17px;background:#fff;border:1px solid var(--border);border-radius:12px;font-weight:700;font-size:14px}.quick-index small{display:block;color:var(--muted);font-weight:400}.subtle{color:var(--muted);font-size:14px}
@media(max-width:1120px){.desktop-nav{gap:9px}.desktop-nav a{font-size:13px}.brand{min-width:150px}.header-inner{gap:14px}.header-cta{padding:0 15px}}
@media(max-width:980px){.site-header{height:60px}.header-inner{justify-content:space-between}.menu-toggle{display:flex}.desktop-nav{display:none}.brand{min-width:unset;position:absolute;left:50%;transform:translateX(-50%)}.brand img{max-height:30px;max-width:155px}.brand-mark{height:30px;width:30px;font-size:18px}.brand-words strong{font-size:15px}.brand-words small{font-size:8px}.header-cta{height:40px;font-size:13px}.hero-inner{min-height:unset}.article-grid{grid-template-columns:1fr}.sidebar{display:none}.intro-band .container{gap:28px}.feature-grid{grid-template-columns:repeat(2,1fr)}.mobile-bottom{position:fixed;bottom:0;left:0;right:0;z-index:80;display:grid;grid-template-columns:repeat(4,1fr);background:#fff;border-top:1px solid var(--border);box-shadow:0 -5px 25px #174b7814}.mobile-bottom a{padding:9px 4px 11px;text-align:center;font-size:13px;font-weight:700}.mobile-bottom a[aria-current=page]{color:var(--blue)}.site-footer{margin-bottom:49px}.back-top{bottom:72px}}
@media(max-width:700px){body{font-size:15px;line-height:1.77}.container{width:calc(100% - 32px)}.hero-inner{display:flex;flex-direction:column;gap:25px;padding:28px 0 36px}.hero-inner>.media{order:-1}.hero-text{width:100%}h1{font-size:29px}h2{font-size:21px}h3{font-size:18px}.lead{font-size:15px}.page-section{padding:27px 0}.section-head{align-items:start;flex-direction:column;gap:3px}.feature-grid,.split,.compare-grid,.card-list,.insight-row,.insight-row:nth-child(even){grid-template-columns:1fr}.insight-row:nth-child(even) .media{order:0}.feature-card{padding:20px}.panel{padding:22px}.media--hero{height:210px}.media--wide{height:180px}.media--card{height:145px}.media--banner{height:155px}.media--portrait{height:260px}.intro-band{padding:27px 0 22px}.intro-band .container{display:flex;flex-direction:column;align-items:stretch;gap:22px}.intro-band h1{font-size:27px}.article-wrap{padding-top:24px}.article>section{margin-bottom:30px}.related-links{grid-template-columns:1fr}.footer-inner{grid-template-columns:1fr 1fr;gap:28px;padding-top:32px}.footer-brand{grid-column:1/-1}.site-footer{margin-top:38px}.quick-index{grid-template-columns:repeat(2,1fr)}.header-cta{padding:0 11px;min-width:70px;height:38px}.editorial-item{gap:12px}.article{font-size:15px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important}}