:root{--bg:#f6fafc;--white:#fff;--wash:#eaf6fa;--wash2:#edf4f8;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--sea:#174b78;--title:#183a56;--text:#31485d;--muted:#687d8e;--border:#dce9f0;--footer:#123653;--radius:17px;--shadow:0 12px 34px rgba(23,75,120,.055)}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;min-width:320px;background:var(--bg);color:var(--text);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif}body.drawer-open{overflow:hidden}img{max-width:100%}a{color:var(--sea);text-underline-offset:4px}a:hover{color:var(--blue)}button{font:inherit;cursor:pointer}button,a{ -webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}.container{width:min(1180px,calc(100% - 56px));margin-inline:auto}main{overflow:clip}h1,h2,h3,p{margin-top:0}h1,h2,h3{color:var(--title);line-height:1.4}h1{font-size:clamp(32px,3vw,40px);letter-spacing:-.045em}h2{font-size:26px}h3{font-size:20px}p{margin-bottom:1.15em}small{font-size:13px}.eyebrow{display:block;margin-bottom:10px;color:#138fa8;font-size:12px;font-weight:800;letter-spacing:.15em;text-transform:uppercase}.lead{font-size:17px;color:#425d71;max-width:780px}.muted{color:var(--muted)}.section{margin-top:58px;margin-bottom:58px}.section-heading{margin-bottom:24px}.section-heading h2{margin-bottom:8px}.section-heading p{max-width:760px;color:var(--muted)}.surface{background:#fff;border:1px solid var(--border);border-radius:var(--radius)}.soft{background:var(--wash);border-radius:var(--radius)}.skip-link{position:fixed;z-index:200;top:-70px;left:12px;padding:8px 16px;background:#fff}.skip-link:focus{top:10px}
.site-header{position:relative;z-index:20;background:white}.topbar{height:72px;display:flex;align-items:center;gap:22px}.brand{display:flex;align-items:center;flex:none;text-decoration:none}.brand .media{background:transparent;border:0;overflow:visible}.media--logo{width:auto;height:38px;max-width:240px;min-height:0}.media--logo img{max-height:38px}.brand-text{font-size:26px;font-weight:900;line-height:1;color:var(--sea);letter-spacing:-.05em}.brand-text>span{color:#1393a5}.brand-text small{display:block;font-size:9px;letter-spacing:.17em;margin-top:5px}.topbar-caption{margin:0 auto;color:var(--muted);font-size:13px;letter-spacing:.1em}.entry-button{display:inline-flex;align-items:center;justify-content:center;min-height:42px;padding:8px 21px;gap:12px;border-radius:9px;background:var(--sea);color:white;text-decoration:none;font-size:14px;font-weight:700;white-space:nowrap}.entry-button:hover{background:#116d9f;color:#fff}.desktop-nav{background:var(--sea)}.nav-inner{display:flex;align-items:center;justify-content:space-between;gap:8px;min-height:48px}.desktop-nav a{display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:8px 12px;color:#e5f5ff;font-size:14px;font-weight:650;text-decoration:none;border-bottom:3px solid transparent;white-space:nowrap}.desktop-nav a:hover,.desktop-nav a.active{color:white;border-bottom-color:var(--cyan)}.quickbar{background:#edf8fb;border-bottom:1px solid var(--border)}.quickbar-inner{padding-block:12px;display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;font-size:12px;color:var(--muted)}.quickbar-inner span{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.quickbar-inner a{text-decoration:none;color:#176184;font-weight:700}.menu-toggle{display:none;border:0;background:none;width:40px;height:40px;padding:10px;flex-direction:column;justify-content:space-evenly}.menu-toggle span{display:block;height:2px;background:var(--sea);width:100%;border-radius:3px}.drawer-overlay{position:fixed;inset:0;z-index:50;background:rgba(13,44,70,.48);opacity:0;visibility:hidden;pointer-events:none;transition:opacity .2s,visibility .2s}.site-drawer{position:fixed;inset:0 auto 0 0;z-index:51;width:min(86vw,344px);background:white;overflow-y:auto;transform:translateX(-103%);visibility:hidden;pointer-events:none;transition:transform .22s,visibility .22s;box-shadow:var(--shadow)}.drawer-open .drawer-overlay{opacity:1;visibility:visible;pointer-events:auto}.drawer-open .site-drawer{transform:translateX(0);visibility:visible;pointer-events:auto}.drawer-head{display:flex;align-items:center;justify-content:space-between;padding:18px 20px;border-bottom:1px solid var(--border);color:var(--sea)}.drawer-close{border:none;background:var(--wash);border-radius:8px;width:40px;height:40px;font-size:28px;line-height:1}.drawer-group{padding:16px 24px;border-bottom:1px solid var(--border)}.drawer-group h2{font-size:13px;color:var(--muted);margin-bottom:8px}.drawer-group a{display:block;padding:8px 0;font-size:15px;font-weight:650;text-decoration:none}.bottom-nav{display:none}.back-top{position:fixed;right:22px;bottom:24px;z-index:15;border:1px solid var(--border);border-radius:50%;width:44px;height:44px;background:#fff;color:var(--sea);box-shadow:var(--shadow);font-size:23px}.back-top[hidden]{display:none}
.media{display:flex;justify-content:center;align-items:center;width:100%;min-width:0;overflow:hidden;border-radius:14px;background:var(--wash);border:1px solid var(--border)}.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:400px;margin-inline:auto}.media--wide{height:auto;min-height:110px;aspect-ratio:2.8}.media--missing .placeholder-mark{width:65px;height:65px;border:2px solid rgba(23,75,120,.13);border-radius:18px;position:relative;transform:rotate(-9deg)}.placeholder-mark::after{content:"";position:absolute;inset:15px;border:2px solid rgba(23,75,120,.10);border-radius:50%}
.hero{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);align-items:center;gap:45px;padding:52px 0 32px}.hero h1{max-width:620px;margin-bottom:18px}.hero-copy p{max-width:590px}.hero-actions{display:flex;flex-wrap:wrap;gap:14px;margin-top:26px}.btn{display:inline-flex;align-items:center;gap:9px;padding:10px 19px;text-decoration:none;font-weight:700;font-size:14px;border:1px solid var(--sea);border-radius:9px}.btn-primary{color:#fff;background:var(--sea)}.btn-primary:hover{color:#fff;background:#176d9b}.btn-ghost{background:white}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{position:relative;display:flex;flex-direction:column;justify-content:space-between;padding:21px;min-height:175px;background:white;border:1px solid var(--border);border-radius:14px;text-decoration:none;transition:transform .2s,border-color .2s}.topic-card:hover{transform:translateY(-3px);border-color:#9bdbe6}.topic-number{font-size:12px;font-weight:800;color:#159aaf}.topic-card h3{margin:7px 0;font-size:19px}.topic-card p{margin:0;color:var(--muted);font-size:13px;line-height:1.75}.topic-card .arrow{position:absolute;right:20px;top:15px;color:#1b98b3}.editorial{display:grid;grid-template-columns:2fr 1fr;gap:16px}.editorial-main{padding:30px 32px;background:var(--wash)}.editorial-main h3{font-size:25px}.editorial-side{display:grid;gap:16px}.editorial-side article{padding:22px;background:#fff;border:1px solid var(--border);border-radius:var(--radius)}.editorial a,.text-link{font-size:14px;font-weight:800}.split{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}.split.reverse .media{order:-1}.split h2{margin-bottom:16px}.split .media{min-width:0}.band{padding:35px;background:var(--wash2);border-radius:18px}.knowledge-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.knowledge-grid article{padding:24px;border:1px solid var(--border);background:white;border-radius:var(--radius)}.knowledge-grid h3{margin-bottom:11px}.knowledge-grid p{font-size:14px}.reading-path{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;counter-reset:path}.reading-path div{position:relative;padding:18px 14px 18px 44px;background:white;border-top:3px solid var(--cyan);border-radius:5px}.reading-path div:before{counter-increment:path;content:counter(path,decimal-leading-zero);position:absolute;left:10px;color:#1a96a7;font-weight:800}.reading-path strong{display:block;color:var(--title)}.reading-path span{font-size:13px;color:var(--muted)}.editor-note{padding:20px 24px;border-left:3px solid var(--cyan);background:#eaf6fa;color:var(--text);font-size:14px}
.page-intro{padding-top:42px;padding-bottom:20px}.page-intro .lead{max-width:810px}.page-intro h1{font-size:35px}.article-width{max-width:780px}.prose p,.prose li{line-height:1.85}.prose h2{margin-top:32px}.prose h3{margin-top:25px}.content-grid{display:grid;grid-template-columns:minmax(0,1fr) 240px;gap:50px}.aside-card{position:sticky;top:20px;padding:22px;background:var(--wash);border-radius:14px;align-self:start}.aside-card h2{font-size:20px}.aside-card dl{margin:0}.aside-card dt{font-weight:800;color:var(--sea);margin-top:13px}.aside-card dd{margin:2px 0 8px;font-size:13px;color:var(--muted)}.table-wrap{overflow-x:auto;margin:22px 0;border:1px solid var(--border);border-radius:12px;background:white}table{border-collapse:collapse;width:100%;min-width:580px;font-size:14px;line-height:1.6}th,td{text-align:left;padding:15px 17px;border-bottom:1px solid var(--border);vertical-align:top}th{background:#eaf6fa;color:var(--sea);font-weight:800}tr:last-child td{border-bottom:0}.steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;list-style:none;margin:22px 0;padding:0;counter-reset:step}.steps li{padding:24px;background:#fff;border:1px solid var(--border);border-radius:12px}.steps li:before{counter-increment:step;content:counter(step,decimal-leading-zero);display:block;font-size:22px;color:#1696ae;font-weight:800;margin-bottom:8px}.steps strong{display:block;color:var(--title);font-size:18px}.steps p{font-size:14px;margin:8px 0 0}.info-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.info-grid article{background:#fff;border:1px solid var(--border);padding:23px;border-radius:var(--radius)}.info-grid p{font-size:14px}.note{padding:19px 22px;background:#eaf6fa;border-left:3px solid var(--cyan);margin:22px 0}.bullet-list{padding-left:24px}.bullet-list li{margin-bottom:10px}.tags{display:flex;gap:9px;flex-wrap:wrap;margin-top:14px}.tags a{padding:6px 11px;text-decoration:none;font-size:13px;border:1px solid #bedce5;border-radius:7px;background:#fff}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.gallery-grid figure{margin:0;padding:15px;background:white;border:1px solid var(--border);border-radius:var(--radius)}.gallery-grid figcaption{padding:15px 5px 4px;font-size:14px;color:var(--text)}.gallery-grid figcaption strong{display:block;font-size:18px;color:var(--title)}.faq-list{display:grid;gap:12px;margin:20px 0}.faq-list details{border:1px solid var(--border);border-radius:10px;background:white;padding:0 18px}.faq-list summary{padding:16px 4px;cursor:pointer;color:var(--title);font-weight:750}.faq-list details[open] summary{border-bottom:1px solid var(--border)}.faq-list details p{padding:15px 4px 5px;margin:0;font-size:14px}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.related-link{display:flex;flex-direction:column;min-height:128px;padding:20px;background:#fff;border:1px solid var(--border);border-radius:12px;text-decoration:none;position:relative}.related-link strong{font-size:18px}.related-link span:nth-child(2){font-size:13px;color:var(--muted);margin-top:6px;padding-right:10px}.related-link span:last-child{position:absolute;right:18px;top:15px}.service-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:28px}.service-grid .surface{padding:26px}
.site-footer{background:var(--footer);color:#eaf7ff;margin-top:65px}.footer-main{display:grid;grid-template-columns:2fr 1fr 1fr;gap:70px;padding:49px 0 36px}.footer-brand{font-size:23px;color:white;text-decoration:none;font-weight:800}.footer-brand small{display:block;font-size:10px;letter-spacing:.18em}.site-footer p{font-size:13px;line-height:1.8;max-width:390px;margin-top:15px;color:#b9d6e6}.site-footer h2{font-size:15px;color:white}.site-footer a:not(.footer-brand){display:block;color:#d4ecf8;text-decoration:none;font-size:13px;margin:8px 0}.site-footer a:hover{text-decoration:underline}.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;border-top:1px solid rgba(255,255,255,.15);padding:20px 0 24px;color:#b3d1e2;font-size:12px}
@media(max-width:980px){.container{width:min(100% - 44px,1180px)}.topbar{height:64px;justify-content:space-between;gap:10px}.menu-toggle{display:flex}.brand{margin-right:auto}.topbar-caption,.desktop-nav{display:none}.brand .media--logo,.brand .media--logo img{max-height:30px}.entry-button{min-height:40px;padding:6px 13px;font-size:13px}.hero{gap:25px}.topic-grid{grid-template-columns:repeat(3,1fr)}.quickbar-inner{justify-content:flex-start}.content-grid{grid-template-columns:minmax(0,1fr) 220px;gap:24px}}
@media(max-width:760px){.hero{grid-template-columns:1fr;padding-top:34px}.hero .media{max-width:650px;margin:auto}.topic-grid{grid-template-columns:repeat(2,1fr)}.editorial{grid-template-columns:1fr}.editorial-side{grid-template-columns:repeat(2,1fr)}.split,.content-grid,.service-grid{grid-template-columns:1fr}.split.reverse .media{order:0}.aside-card{position:static}.info-grid,.knowledge-grid,.related-grid{grid-template-columns:repeat(2,1fr)}.steps{grid-template-columns:1fr}.footer-main{gap:26px;grid-template-columns:1.6fr 1fr 1fr}.page-intro h1{font-size:30px}}
@media(max-width:640px){.container{width:calc(100% - 32px)}body{font-size:15px;line-height:1.75}h1{font-size:29px}h2{font-size:22px}h3{font-size:18px}.page-intro h1{font-size:27px}.lead{font-size:15px}.section{margin-top:36px;margin-bottom:36px}.hero{padding:29px 0 6px}.hero-actions{gap:10px}.btn{padding:9px 14px}.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;min-height:70px}.media--logo{max-width:130px}.brand-text{font-size:19px}.brand-text small{font-size:7px}.entry-button{font-size:12px;padding:6px 10px}.topic-grid,.editorial-side,.knowledge-grid,.info-grid,.related-grid,.gallery-grid{grid-template-columns:1fr}.topic-card{min-height:135px;padding:19px}.editorial-main{padding:23px}.editorial-main h3{font-size:21px}.split{gap:17px}.band{padding:22px 18px}.reading-path{grid-template-columns:1fr 1fr;gap:9px}.reading-path div{padding:14px 12px 14px 37px}.page-intro{padding-top:30px}.footer-main{grid-template-columns:1fr 1fr;gap:20px;padding:36px 0 26px}.footer-main>div:first-child{grid-column:1/-1}.footer-bottom{font-size:11px}.quickbar-inner{gap:9px;font-size:11px}.quickbar-inner span{gap:7px}.bottom-nav{position:fixed;display:grid;grid-template-columns:repeat(4,1fr);z-index:18;bottom:0;left:0;right:0;padding-bottom:env(safe-area-inset-bottom);background:#fff;border-top:1px solid var(--border);box-shadow:0 -5px 20px rgba(23,75,120,.06)}.bottom-nav a{min-height:51px;display:flex;align-items:center;justify-content:center;text-decoration:none;font-size:12px;font-weight:750}.bottom-nav .active{color:#138faa;border-top:2px solid var(--cyan)}body{padding-bottom:calc(54px + env(safe-area-inset-bottom))}.back-top{bottom:calc(68px + env(safe-area-inset-bottom));right:13px}}
@media(max-height:480px) and (max-width:640px){.bottom-nav{position:static}body{padding-bottom:0}.back-top{bottom:14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}