:root{--bg:#f5fbff;--surface:#fff;--soft:#eaf7fc;--soft2:#dff5fb;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--navy:#174b78;--dark:#173b60;--text:#2d4359;--muted:#687f93;--line:#dcebf3;--footer:#123653;--radius:20px;--shadow:0 12px 38px rgba(23,75,120,.07)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif}body.drawer-open{overflow:hidden}a{color:inherit;text-decoration:none}a:hover{color:var(--blue)}button{font:inherit;cursor:pointer}img{max-width:100%}h1,h2,h3,h4,p{margin-top:0}h1,h2,h3{line-height:1.38;color:var(--dark)}h1{font-size:clamp(27px,3.2vw,40px);letter-spacing:-.02em}h2{font-size:clamp(20px,2.4vw,26px)}h3{font-size:clamp(17px,1.8vw,20px)}p{margin-bottom:1.1em}.container{max-width:1160px;margin:0 auto;padding:0 24px}.skip-link{position:absolute;top:-50px;left:12px;z-index:100;background:#fff;padding:8px}.skip-link:focus{top:8px}.site-header{height:72px;position:sticky;top:0;z-index:30;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line);backdrop-filter:blur(12px)}.header-inner{display:flex;align-items:center;gap:26px;height:100%}.brand{display:inline-flex;align-items:center;flex:none;min-width:112px}.brand-logo{display:block;max-height:38px;width:auto;height:auto;object-fit:contain}.brand-fallback{display:inline-flex;color:var(--dark);font-size:24px;line-height:1;font-weight:900;letter-spacing:.06em}.brand-fallback span{color:var(--sky)}.desktop-nav{display:flex;align-items:center;gap:clamp(8px,1.1vw,20px);margin-left:auto;white-space:nowrap}.nav-link{font-size:14px;font-weight:600;padding:22px 3px 20px;border-bottom:3px solid transparent}.nav-link.is-current{color:var(--blue);border-color:var(--cyan)}.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;line-height:1.2;box-shadow:0 6px 16px rgba(23,135,219,.18)}.main-btn:hover{color:#fff;filter:brightness(.95)}.top-entry{font-size:14px;margin-left:auto}.menu-toggle{display:none;width:42px;height:42px;flex:none;border:1px solid var(--line);border-radius:12px;background:#fff;padding:11px}.menu-toggle span{display:block;height:2px;background:var(--navy);margin:4px 0}.drawer-backdrop{position:fixed;inset:0;z-index:39;background:rgba(13,38,60,.5);visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer{position:fixed;z-index:40;inset:0 auto 0 0;width:min(86vw,340px);max-width:100%;background:#fff;transform:translateX(-105%);visibility:hidden;transition:transform .25s,visibility .25s;overflow-y:auto;box-shadow:0 20px 50px rgba(0,0,0,.2);padding:18px 22px 35px}.drawer-open .drawer{transform:translateX(0);visibility:visible}.drawer-open .drawer-backdrop{visibility:visible;opacity:1;pointer-events:auto}.drawer-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:15px}.drawer-close{font-size:32px;line-height:1;border:0;background:none;color:var(--dark)}.drawer nav>a{display:block;padding:10px 4px;border-bottom:1px solid var(--line);font-weight:600}.drawer-label{margin:20px 0 4px;color:var(--blue);font-size:12px;font-weight:800;letter-spacing:.1em}.mobile-bottom{display:none}.eyebrow{color:var(--blue);letter-spacing:.14em;font-size:12px;font-weight:800;text-transform:uppercase;margin-bottom:11px}.section{padding:45px 0}.section-tight{padding:25px 0 40px}.section-head{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:25px}.section-head p{max-width:560px;margin:0}.text-link{font-size:14px;font-weight:800;color:var(--blue)}.hero{padding:56px 0 38px}.hero-grid{display:grid;grid-template-columns:1.04fr .96fr;align-items:center;gap:48px}.hero .lead{max-width:610px;font-size:17px;line-height:1.85}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:25px}.ghost-btn{display:inline-flex;align-items:center;justify-content:center;border:1px solid #c5e3f2;padding:0 20px;height:42px;border-radius:100px;color:var(--navy);font-weight:700;background:#fff}.hero-highlight{padding:14px 20px;margin-top:24px;background:var(--soft);border-left:3px solid var(--cyan);border-radius:0 12px 12px 0;font-size:14px}.media{width:100%;display:flex;align-items:center;justify-content:center;overflow:hidden;border-radius:16px;background:linear-gradient(150deg,#def3fb,#f4fcff);border:1px solid #d8edf6}.media--hero{height:315px}.media--landscape{height:215px}.media--banner{height:220px}.media--square{height:200px}.media--portrait{height:310px;max-width:360px;margin:auto}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--empty{background:linear-gradient(135deg,#e1f6fb 0%,#f1faff 58%,#dceff8 100%)}.media-mark{display:block;width:26%;aspect-ratio:1;border-radius:30%;border:18px solid rgba(37,182,232,.12);transform:rotate(-22deg);position:relative}.media-mark:after{content:'';position:absolute;inset:23%;border-radius:50%;background:rgba(23,135,219,.12)}.feature-card,.simple-card,.article-panel,.soft-panel,.stat-panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}.feature-card{overflow:hidden}.feature-card .card-body{padding:21px 23px 24px}.feature-card h3{margin-bottom:8px}.feature-card p{font-size:14px;color:var(--muted);margin-bottom:12px}.feature-card a.stretched{color:var(--blue);font-weight:800;font-size:14px}.card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.card-grid--two{grid-template-columns:repeat(2,minmax(0,1fr))}.simple-card{padding:25px}.simple-card .card-index{font-size:12px;letter-spacing:.14em;color:var(--blue);font-weight:800}.simple-card p{font-size:14px;margin:9px 0 0;color:var(--muted)}.simple-card h3{margin:10px 0 0}.simple-card:hover{border-color:#b2e2f4;transform:translateY(-2px);transition:.2s}.band{background:var(--soft);padding:48px 0}.split{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:center}.split--text{grid-template-columns:1.2fr .8fr}.bullets{padding-left:20px}.bullets li{margin-bottom:10px}.list-rows{display:grid;gap:0}.list-row{display:flex;align-items:baseline;justify-content:space-between;gap:20px;padding:18px 0;border-bottom:1px solid var(--line)}.list-row:first-child{border-top:1px solid var(--line)}.list-row strong{color:var(--dark);font-size:17px}.list-row small{color:var(--muted)}.list-row span{color:var(--blue)}.page-intro{padding:50px 0 34px}.page-intro .container{max-width:1160px}.page-intro p.intro-copy{max-width:790px;font-size:17px}.intro-rule{width:72px;height:4px;background:linear-gradient(90deg,var(--cyan),var(--blue));border-radius:4px;margin:25px 0}.article-wrap{max-width:860px;margin:0 auto;padding:0 20px}.article-body{font-size:16px;line-height:1.85}.article-body p{margin-bottom:1.25em}.article-body h2{margin-top:44px;margin-bottom:16px}.article-body h3{margin-top:26px}.article-body ul,.article-body ol{padding-left:23px}.article-body li{margin-bottom:9px}.article-panel{padding:28px 32px;margin:28px 0}.article-panel h2,.article-panel h3{margin-top:0}.article-panel p:last-child{margin-bottom:0}.soft-panel{background:var(--soft);padding:28px 32px;margin:28px 0;box-shadow:none}.aside-note{padding:18px 22px;border-left:3px solid var(--cyan);background:#fff;border-radius:0 12px 12px 0;margin:28px 0}.page-section{padding:26px 0 45px}.section-kicker{font-weight:800;color:var(--blue);font-size:12px;letter-spacing:.1em}.comparison{display:grid;grid-template-columns:1fr 1fr;gap:22px}.comparison>article{border-top:4px solid var(--cyan);padding:26px;background:#fff;border-radius:0 0 16px 16px}.comparison>article:nth-child(2){border-color:var(--blue)}.comparison h3{margin-bottom:10px}.comparison p{margin-bottom:0}.mini-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.mini-grid .simple-card{box-shadow:none}.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:16px;background:#fff;margin:24px 0}table{border-collapse:collapse;width:100%;min-width:520px;font-size:15px}th,td{text-align:left;padding:15px 18px;vertical-align:top;border-bottom:1px solid var(--line)}th{background:#eaf7fc;color:var(--dark)}tr:last-child td{border-bottom:0}.steps{counter-reset:steps;display:grid;gap:16px;margin:24px 0}.step{display:flex;gap:18px;align-items:start;padding:18px;border:1px solid var(--line);border-radius:14px;background:#fff}.step:before{counter-increment:steps;content:counter(steps,decimal-leading-zero);font-size:20px;font-weight:800;color:var(--blue)}.step h3{margin:0 0 5px}.step p{margin:0}.timeline{border-left:2px solid #bce7f4;padding:5px 0 6px 24px;margin-left:8px}.timeline-item{position:relative;padding:0 0 20px}.timeline-item:before{content:'';width:12px;height:12px;background:var(--cyan);position:absolute;top:9px;left:-31px;border-radius:50%;border:3px solid var(--bg)}.timeline-item h3{margin:0 0 6px}.timeline-item p{margin:0}.faq details{padding:17px 20px;border:1px solid var(--line);background:#fff;border-radius:12px;margin-bottom:11px}.faq summary{cursor:pointer;color:var(--dark);font-weight:700}.faq details p{margin:12px 0 0}.related{margin:45px 0 55px;padding-top:28px;border-top:2px solid var(--line)}.related h2{margin-bottom:20px}.related-links{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-links a{display:flex;justify-content:space-between;gap:10px;padding:16px;border:1px solid var(--line);background:#fff;border-radius:12px;color:var(--dark);font-weight:700}.related-links a span{color:var(--blue)}.site-footer{margin-top:45px;background:var(--footer);color:#eaf7ff;padding:48px 0 0}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px}.site-footer p{font-size:14px;max-width:330px}.site-footer .footer-note{opacity:.72}.footer-brand .brand-fallback{color:#fff}.footer-grid h2{font-size:16px;color:#fff;margin:0 0 14px}.footer-grid nav a{display:block;font-size:14px;padding:3px 0;color:#eaf7ff}.footer-grid nav a:hover{color:#76e7ed}.footer-bottom{display:flex;justify-content:space-between;gap:15px;border-top:1px solid rgba(255,255,255,.16);padding-top:17px;padding-bottom:20px;margin-top:37px;font-size:12px;color:#b8d4e5}.to-top{position:fixed;right:20px;bottom:22px;z-index:20;width:44px;height:44px;border:0;border-radius:50%;background:var(--navy);color:#fff;opacity:0;visibility:hidden;transform:translateY(10px);transition:.2s}.to-top.is-visible{opacity:1;visibility:visible;transform:none}.tag{display:inline-block;font-size:12px;font-weight:800;color:var(--navy);background:var(--soft);padding:2px 10px;border-radius:20px}.caption{font-size:13px;color:var(--muted);margin:9px 0 0}.quote{font-size:22px;color:var(--dark);font-weight:700;border-left:4px solid var(--cyan);padding:6px 0 6px 22px;margin:28px 0}.editor-grid{display:grid;grid-template-columns:1.35fr .65fr;gap:30px}.editor-grid .article-panel{margin:0}.toc{position:sticky;top:100px;padding:20px;background:var(--soft);border-radius:14px}.toc a{display:block;padding:6px 0;color:var(--navy);font-size:14px}.pill-list{display:flex;flex-wrap:wrap;gap:9px}.pill-list a{padding:8px 14px;background:white;border:1px solid var(--line);border-radius:30px;font-size:14px}
@media(max-width:1050px){.desktop-nav{gap:7px}.header-inner{gap:13px}.nav-link{font-size:13px}.top-entry{padding:0 14px}}
@media(max-width:980px){.desktop-nav{display:none}.menu-toggle{display:block}.header-inner{justify-content:space-between}.brand{min-width:0}.top-entry{margin-left:0}.site-header{height:61px}.brand-logo{max-height:30px}.hero-grid{gap:28px}.footer-grid{grid-template-columns:1.5fr 1fr 1fr}.editor-grid{grid-template-columns:1fr}.toc{position:static}}
@media(max-width:700px){body{font-size:15px}.container{padding:0 16px}.site-header{height:59px}.menu-toggle{width:40px;height:40px}.brand-fallback{font-size:21px}.top-entry{height:40px;padding:0 13px;font-size:13px}.hero{padding:29px 0}.hero-grid{grid-template-columns:1fr;gap:22px}.hero-grid .hero-media{grid-row:1}.hero .lead,.page-intro p.intro-copy{font-size:15px}.hero-highlight{padding:12px}.media--hero{height:215px}.media--landscape{height:165px}.media--banner{height:150px}.media--square{height:160px}.media--portrait{height:255px}.section{padding:28px 0}.section-tight{padding:20px 0 30px}.band{padding:30px 0}.section-head{align-items:start;flex-direction:column;gap:4px;margin-bottom:19px}.card-grid,.card-grid--two,.mini-grid,.split,.split--text,.comparison{grid-template-columns:1fr}.feature-card .card-body{padding:17px}.simple-card{padding:20px}.split{gap:20px}.page-intro{padding:29px 0 18px}.page-section{padding:18px 0 28px}.article-wrap{padding:0 16px}.article-body{font-size:15px}.article-body h2{margin-top:28px}.article-panel,.soft-panel{padding:20px;margin:20px 0}.related{margin:30px 0}.related-links{grid-template-columns:1fr}.list-row{align-items:start}.list-row small{display:block}.footer-grid{grid-template-columns:1fr 1fr;gap:26px}.footer-grid>div:first-child{grid-column:1/-1}.footer-bottom{flex-direction:column}.site-footer{padding-top:34px;margin-top:20px;padding-bottom:57px}.mobile-bottom{position:fixed;bottom:0;left:0;right:0;z-index:25;display:flex;justify-content:space-around;padding:6px 0 max(6px,env(safe-area-inset-bottom));border-top:1px solid var(--line);background:#fff}.mobile-bottom a{font-size:12px;font-weight:700;color:var(--navy);padding:4px 12px}.mobile-bottom a[aria-current="page"]{color:var(--blue)}.to-top{bottom:76px;right:13px}.steps{gap:10px}.step{padding:14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}