:root{--bg:#F5FBFF;--white:#fff;--soft:#EAF7FC;--pale:#DFF5FB;--aqua:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--deep:#174B78;--title:#173B60;--text:#2D4359;--muted:#687F93;--line:#DCEBF3;--footer:#123653;--shadow:0 14px 38px rgba(23,75,120,.07)}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:88px}body{margin:0;color:var(--text);background:var(--bg);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-x:hidden}a{color:var(--deep);text-decoration:none}a:hover{color:var(--blue)}button{font:inherit;cursor:pointer}img{max-width:100%;height:auto}h1,h2,h3,h4,p{margin-top:0}h1,h2,h3{color:var(--title);line-height:1.38}h1{font-size:clamp(27px,3.2vw,40px);letter-spacing:-.035em}h2{font-size:clamp(21px,2.25vw,26px)}h3{font-size:19px}p{margin-bottom:1.1em}.wrap{width:min(100% - 48px,1160px);margin-inline:auto}.skip-link{position:absolute;left:12px;top:-100px;z-index:100;background:white;padding:10px}.skip-link:focus{top:10px}
.site-header{background:white;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}.header-inner{height:72px;display:flex;align-items:center;gap:23px}.brand{display:flex;align-items:center;flex:none;min-width:155px}.brand img{display:block;width:auto;max-width:165px;height:37px;object-fit:contain}.brand-mark,.footer-brand{font-weight:900;letter-spacing:.03em;color:var(--deep);font-size:23px}.desktop-nav{display:flex;align-items:center;justify-content:center;gap:3px;margin-left:auto}.desktop-nav a{font-size:14px;white-space:nowrap;color:var(--deep);font-weight:700;padding:10px 10px;border-radius:9px}.desktop-nav a:hover,.desktop-nav a.is-active{color:var(--blue);background:var(--soft)}.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;box-shadow:0 7px 15px rgba(23,135,219,.17)}.main-btn:hover{color:#fff;filter:brightness(.95)}.header-cta{font-size:14px;flex:none}.menu-toggle{display:none;width:40px;height:40px;flex:none;background:transparent;border:1px solid var(--line);border-radius:10px;padding:10px}.menu-toggle span{height:2px;background:var(--deep);display:block;margin:4px 0}.menu-overlay{visibility:hidden;opacity:0;pointer-events:none;position:fixed;inset:0;background:rgba(8,37,64,.48);z-index:59;transition:opacity .22s,visibility .22s}.mobile-menu{position:fixed;top:0;bottom:0;left:0;width:min(86vw,340px);background:#fff;z-index:60;transform:translateX(-103%);visibility:hidden;pointer-events:none;transition:transform .24s,visibility .24s;overflow-y:auto;box-shadow:16px 0 45px rgba(3,27,54,.12)}body.menu-open{overflow:hidden}body.menu-open .menu-overlay{opacity:1;visibility:visible;pointer-events:auto}body.menu-open .mobile-menu{transform:translateX(0);visibility:visible;pointer-events:auto}.drawer-head{padding:20px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.drawer-brand{font-size:21px;font-weight:900}.drawer-brand small,.footer-brand small{font-size:10px;display:block;letter-spacing:.15em}.menu-close{border:0;background:var(--soft);color:var(--deep);font-size:30px;width:40px;height:40px;line-height:1;border-radius:10px}.drawer-body{padding:10px 22px 32px}.drawer-label{font-size:12px;font-weight:900;color:var(--blue);margin:20px 0 4px;letter-spacing:.1em}.drawer-body>a{display:block;border-bottom:1px solid var(--line);padding:11px 6px;font-size:15px}
main{min-height:55vh}.section{padding-block:45px}.section-tight{padding-block:30px}.section-heading{margin-bottom:24px;max-width:800px}.section-heading .eyebrow,.eyebrow{display:block;color:#087eae;font-size:12px;font-weight:900;letter-spacing:.13em;margin-bottom:9px}.lead{font-size:17px;line-height:1.85;color:var(--text);max-width:780px}.muted{color:var(--muted)}.hero{padding:52px 0 45px;background:linear-gradient(124deg,#eefbff 10%,#d9f2fb 64%,#f6fbff 100%);border-bottom:1px solid var(--line)}.hero-grid{display:grid;grid-template-columns:1.04fr .96fr;gap:40px;align-items:center}.hero h1{max-width:660px;margin-bottom:17px}.hero p{font-size:17px;max-width:600px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px}.ghost-btn{border:1px solid #9ddbe9;color:var(--deep);border-radius:999px;padding:8px 19px;background:#fff;font-weight:700}.media{margin:0;display:flex;justify-content:center;align-items:center;width:100%;overflow:hidden;background:var(--soft);border-radius:14px;min-height:150px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--placeholder{position:relative;background:linear-gradient(135deg,#dff5fb,#bfeaf6 58%,#e7f9fc);border:1px solid #c5e7f3}.media-decoration{display:block;width:48%;aspect-ratio:1;border:20px solid rgba(37,182,232,.12);border-radius:50%;position:relative}.media-decoration::after{content:'';position:absolute;inset:26%;border:12px solid rgba(23,135,219,.16);border-radius:50%}.hero-media{height:315px}.story-media{height:210px}.strip-media{height:215px}.portrait-media{height:330px}.media img{max-height:inherit}.hero-media img,.story-media img,.strip-media img,.portrait-media img{max-height:100%}
.card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.two-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.feature-card,.info-card{background:white;border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow)}.feature-card h3,.info-card h3{margin:2px 0 12px}.feature-card p,.info-card p{color:var(--muted);margin-bottom:12px}.feature-card a.more,.more{font-weight:800;color:#137eaa}.number{font-size:13px;letter-spacing:.1em;font-weight:900;color:#1296bd}.split-section{display:grid;grid-template-columns:1fr 1fr;gap:34px;align-items:center}.alt-background{background:#eaf7fc}.paper{background:white;border:1px solid var(--line);border-radius:17px;padding:32px}.topic-list{list-style:none;margin:0;padding:0}.topic-list li{padding:14px 0;border-bottom:1px solid var(--line)}.topic-list li:last-child{border-bottom:0}.topic-list a{font-weight:750}.topic-list small{display:block;color:var(--muted);font-size:13px}.tag{display:inline-block;font-weight:800;font-size:12px;color:#0b7b9b;background:#dff5fb;border-radius:50px;padding:3px 11px;margin-bottom:12px}.pill-row{display:flex;flex-wrap:wrap;gap:10px}.pill-row a{background:#fff;border:1px solid #c7e8f1;padding:8px 17px;border-radius:999px;font-weight:700;font-size:14px}.article-head{padding:48px 0 30px;background:linear-gradient(115deg,#e9f9fd,#f8fcff);border-bottom:1px solid var(--line)}.article-head h1{max-width:850px;font-size:clamp(25px,3vw,34px)}.article-head .lead{max-width:840px}.crumb{color:var(--muted);font-size:13px;margin-bottom:18px}.crumb a{color:var(--blue)}.article-shell{display:grid;grid-template-columns:minmax(0,800px) minmax(185px,1fr);gap:35px;align-items:start;padding-block:42px}.article-body h2{margin-top:32px}.article-body h3{margin-top:24px}.article-body p,.article-body li{line-height:1.82}.article-body ul,.article-body ol{padding-left:22px}.aside-panel{position:sticky;top:100px;background:white;border:1px solid var(--line);border-radius:14px;padding:20px}.aside-panel h2{font-size:17px}.aside-panel a{display:block;padding:9px 0;border-bottom:1px solid var(--line);font-size:14px;font-weight:700}.aside-panel a:last-child{border:0}.quote-panel{border-left:4px solid var(--aqua);background:var(--soft);padding:22px 26px;margin:24px 0;border-radius:0 10px 10px 0}.quote-panel p{margin:0}.comparison{width:100%;border-collapse:collapse;margin:18px 0 26px;background:#fff;font-size:15px}.comparison th,.comparison td{text-align:left;vertical-align:top;border:1px solid var(--line);padding:13px 15px}.comparison th{background:#ddf4fa;color:var(--title)}.table-scroll{overflow-x:auto}.timeline{border-left:2px solid #73cfe2;padding-left:26px;margin-left:12px}.timeline-item{position:relative;margin:0 0 30px}.timeline-item::before{content:'';width:12px;height:12px;border-radius:50%;background:var(--sky);position:absolute;left:-33px;top:7px}.timeline-item h3{margin:0 0 8px}.related{margin-top:34px;padding:24px 0;border-top:1px solid var(--line)}.related h2{font-size:21px}.related-links{display:flex;flex-wrap:wrap;gap:12px}.related-links a{display:inline-flex;align-items:center;padding:9px 15px;border:1px solid #bddfec;border-radius:10px;background:#fff;font-weight:750;font-size:14px}.fact-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:22px 0}.fact-strip>div{background:var(--soft);border-radius:13px;padding:20px}.fact-strip strong{display:block;color:var(--deep);font-size:21px}.fact-strip span{font-size:13px;color:var(--muted)}.visual-gallery{display:grid;grid-template-columns:1.1fr .9fr;gap:22px}.visual-gallery>div{background:white;border:1px solid var(--line);padding:22px;border-radius:16px}.visual-gallery h3{margin-top:18px}.rule-step{counter-increment:steps;position:relative;border:1px solid var(--line);background:#fff;border-radius:12px;padding:18px 20px 18px 62px;margin-bottom:14px}.rule-step::before{content:counter(steps,decimal-leading-zero);position:absolute;left:18px;top:17px;color:var(--blue);font-weight:900}.rule-steps{counter-reset:steps}.faq-item{border-bottom:1px solid var(--line);padding:15px 0}.faq-item h3{font-size:17px;margin-bottom:7px}.faq-item p{margin-bottom:0}.note{font-size:14px;color:var(--muted)}
.site-footer{background:var(--footer);color:#eaf7ff;margin-top:20px;padding:42px 0 20px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:60px}.footer-grid h2{font-size:16px;color:#eaf7ff;margin-bottom:14px}.footer-grid p{max-width:440px;color:#c6e0ed;font-size:14px}.footer-brand{color:#fff;display:inline-block;margin-bottom:10px}.footer-grid a:not(.footer-brand){display:block;color:#cfe6f1;font-size:14px;margin:7px 0}.footer-grid a:hover{color:#fff}.footer-bottom{display:flex;justify-content:space-between;gap:20px;border-top:1px solid rgba(255,255,255,.15);padding-top:18px;margin-top:28px;color:#c6deed;font-size:12px}.bottom-nav{display:none}.back-top{position:fixed;bottom:22px;right:20px;width:44px;height:44px;background:var(--deep);color:white;border:0;border-radius:50%;box-shadow:var(--shadow);z-index:40;opacity:0;visibility:hidden;transition:.2s}.back-top.visible{opacity:1;visibility:visible}
@media(max-width:1100px){.desktop-nav{gap:0}.desktop-nav a{padding-inline:7px;font-size:13px}.header-inner{gap:12px}.brand{min-width:120px}}
@media(max-width:980px){.desktop-nav{display:none}.menu-toggle{display:block}.header-inner{justify-content:space-between;height:61px}.brand{margin:0 auto;min-width:0}.brand img{height:29px;max-width:132px}.brand-mark{font-size:19px}.header-cta{height:40px;padding:0 14px}.article-shell{grid-template-columns:minmax(0,1fr)}.aside-panel{position:static;display:none}.wrap{width:min(100% - 40px,1160px)}}
@media(max-width:680px){html{scroll-padding-top:70px}body{font-size:15px}.wrap{width:calc(100% - 32px)}.section{padding-block:29px}.hero{padding-block:27px}.hero-grid{grid-template-columns:1fr;gap:22px}.hero-grid>.hero-copy{order:2}.hero-grid>.hero-media{order:1}.hero h1{font-size:29px}.hero p,.lead{font-size:15.5px}.hero-media{height:205px}.card-grid,.two-grid,.split-section,.visual-gallery,.fact-strip,.footer-grid{grid-template-columns:1fr}.feature-card,.info-card,.paper{padding:21px}.section-heading{margin-bottom:17px}.story-media{height:158px}.strip-media{height:155px}.portrait-media{height:260px}.split-section{gap:19px}.article-head{padding:27px 0 22px}.article-head h1{font-size:26px}.article-shell{padding-block:23px}.article-body h2{margin-top:26px}.comparison{font-size:13px}.comparison th,.comparison td{padding:10px}.footer-grid{gap:14px}.site-footer{padding:30px 0 82px}.footer-bottom{flex-direction:column;gap:2px;margin-top:16px}.bottom-nav{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid var(--line);z-index:48;padding-bottom:env(safe-area-inset-bottom)}.bottom-nav a{text-align:center;font-size:13px;font-weight:800;padding:11px 4px;color:var(--deep)}.bottom-nav a.is-active{color:var(--blue);background:var(--soft)}.back-top{bottom:77px;right:14px;width:39px;height:39px}.media-decoration{border-width:13px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}