:root{--bg:#f6fafc;--surface:#fff;--sea:#174b78;--deep:#183a56;--text:#31485d;--muted:#687d8e;--aqua:#25c8d1;--blue:#1787db;--line:#dce9f0;--pale:#eaf6fa;--footer:#123653;--r:16px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-x:clip}body.drawer-open{overflow:hidden}a{color:#086da8;text-underline-offset:3px}a:hover{color:#075181}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #f4ac41;outline-offset:3px}button{font:inherit;cursor:pointer}.shell{width:min(100% - 56px,1180px);margin-inline:auto}.skip-link{position:absolute;top:-80px;left:16px;padding:8px 14px;background:#fff;z-index:110}.skip-link:focus{top:12px}.site-header{background:#fff;border-bottom:1px solid var(--line)}.topbar{height:72px;display:flex;align-items:center;gap:28px}.site-brand{display:flex;align-items:center;flex:0 1 270px;min-width:0;text-decoration:none;color:var(--deep)}.site-brand .media--logo{max-width:220px}.site-brand .brand-fallback{display:none;font-size:23px;letter-spacing:2px;font-weight:800;line-height:1.1}.brand-fallback span{color:#087da1}.brand-fallback small{display:block;font-size:9px;letter-spacing:2px;margin-top:4px}.site-brand:has(.media--placeholder) .media{display:none}.site-brand:has(.media--placeholder) .brand-fallback{display:block}.header-position{margin-inline:auto;color:#52758b;font-size:14px;letter-spacing:2px}.entry-button{border-radius:9px;background:#174b78;color:#fff;text-decoration:none;padding:10px 24px;font-weight:700;white-space:nowrap}.entry-button:hover{background:#116294;color:#fff}.entry-button span{margin-left:5px}.channel-nav{background:var(--sea)}.channel-inner{display:flex;align-items:stretch;gap:0;min-height:48px}.channel-nav a{display:flex;align-items:center;justify-content:center;flex:1;padding:10px 12px;color:#eaf7ff;text-decoration:none;white-space:nowrap;font-weight:600;font-size:14px;border-bottom:3px solid transparent}.channel-nav a:hover,.channel-nav 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p{max-width:640px}.hero-actions{display:flex;flex-wrap:wrap;gap:13px;margin-top:24px}.button-primary,.button-outline{display:inline-flex;align-items:center;min-height:44px;padding:9px 20px;border-radius:8px;font-size:15px;font-weight:700;text-decoration:none}.button-primary{background:#174b78;color:#fff}.button-primary:hover{background:#086e96;color:#fff}.button-outline{border:1px solid #9dc7d5;color:#174b78;background:#fff}.button-outline:hover{background:#eaf6fa}.media{display:flex;align-items:center;justify-content:center;min-width:0;width:100%;overflow:hidden;border-radius:14px;background:#eaf6fa}.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--inline{height:220px}.media--logo{height:38px;background:transparent;justify-content:flex-start;border-radius:0}.media--portrait{max-width:310px;margin-inline:auto}.media--wide{height:auto;min-height:90px;max-height:240px}.media--placeholder{position:relative;background:linear-gradient(140deg,#eaf6fa,#d9edf4);border:1px solid #dce9f0}.placeholder-art{width:34%;height:38%;max-width:120px;max-height:92px;border:2px solid #bfdbe5;border-radius:12px;transform:rotate(-8deg);opacity:.6}.placeholder-art:after{content:'';display:block;width:55%;height:45%;border-radius:50%;background:#c9e4ed;margin:14% auto}.feature-grid{display:grid;grid-template-columns:1.3fr 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var(--line);padding-top:18px}.meta{color:#07889c;font-size:13px;font-weight:700}.link-more{font-weight:700;display:inline-block;margin-top:8px}.tri-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;counter-reset:step}.steps>li{list-style:none;padding:22px 20px;background:#fff;border-top:3px solid #25c8d1;border-radius:9px;counter-increment:step}.steps>li::before{content:counter(step,decimal-leading-zero);display:block;font-weight:800;color:#087c99;margin-bottom:7px}.page-intro{padding-block:43px 28px}.page-intro h1{font-size:36px;max-width:920px}.page-intro .lead{max-width:840px}.article-section{padding-block:28px 42px}.article-section+.article-section{border-top:1px solid var(--line)}.article-layout{display:grid;grid-template-columns:minmax(0,760px) minmax(210px,240px);gap:38px;align-items:start}.article-content{min-width:0}.side-panel{background:#edf4f8;border:1px solid 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@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;align-items:center;justify-content:center;gap:5px;width:40px;height:40px;border:1px solid #dae9ef;background:#fff;border-radius:8px;flex:none}.menu-toggle span{display:block;width:19px;height:2px;border-radius:3px;background:var(--deep)}.site-brand{flex:0 1 auto;justify-content:center;max-width:40%}.site-brand .media--logo{height:30px;max-width:175px}.site-brand .brand-fallback{font-size:19px}.header-position,.channel-nav{display:none}.entry-button{min-height:40px;padding:8px 12px;font-size:13px}.drawer-shade{display:block;position:fixed;inset:0;background:rgba(10,32,46,.5);opacity:0;visibility:hidden;pointer-events:none;z-index:90;transition:opacity .18s,visibility .18s}.mobile-drawer{display:flex;position:fixed;inset:0 auto 0 0;width:min(86vw,344px);background:#fff;flex-direction:column;transform:translateX(-101%);visibility:hidden;pointer-events:none;z-index:91;transition:transform .2s,visibility .2s;box-shadow:8px 0 32px #09334a22}.drawer-open .drawer-shade{opacity:1;visibility:visible;pointer-events:auto}.drawer-open .mobile-drawer{transform:none;visibility:visible;pointer-events:auto}.drawer-top{padding:17px 20px;display:flex;justify-content:space-between;border-bottom:1px solid var(--line);color:var(--deep)}.drawer-top button{border:0;background:transparent;font-size:29px;line-height:1}.drawer-scroll{overflow:auto;padding:12px 20px 35px}.drawer-heading{font-weight:800;font-size:13px;color:#647e8c;padding:17px 0 6px;margin:0}.drawer-scroll a{display:block;color:var(--deep);text-decoration:none;padding:9px 0;border-bottom:1px solid #edf4f8}.bottom-nav{display:flex;position:fixed;bottom:0;left:0;right:0;z-index:35;background:#fff;border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom);box-shadow:0 -2px 18px #12365311}.bottom-nav a{flex:1;text-align:center;padding:10px 3px;font-size:13px;font-weight:700;text-decoration:none;color:var(--deep)}.bottom-nav a[aria-current]{color:#087d9a;border-top:3px solid #25c8d1;padding-top:7px}.site-footer{padding-bottom:calc(74px + env(safe-area-inset-bottom))}.back-top{bottom:calc(75px + env(safe-area-inset-bottom))}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.article-layout{grid-template-columns:minmax(0,1fr) 215px;gap:22px}}
@media(max-width:760px){.hero-grid,.feature-grid,.feature-grid.reverse,.editor-grid,.article-layout,.footer-layout{grid-template-columns:1fr}.hero-grid{gap:22px;padding-block:34px}.hero-copy{order:1}.hero-art{order:2}.section{padding-block:36px}.page-intro{padding-block:30px 16px}.page-intro h1{font-size:29px}.section h2{font-size:23px}.tri-grid,.info-matrix,.related,.timeline{grid-template-columns:1fr}.side-panel{position:static}.gallery{grid-template-columns:1fr}.footer-bottom{flex-direction:column}.steps{grid-template-columns:repeat(2,minmax(0,1fr));padding:0}.feature-grid.reverse .media{order:2}}
@media(max-width:640px){body{font-size:15px;line-height:1.78}.shell{width:calc(100% - 32px)}h1{font-size:30px}h2{font-size:22px}h3{font-size:18px}.lead{font-size:15px}.topic-grid{grid-template-columns:1fr 1fr;gap:10px}.topic-tile{padding:15px}.topic-tile strong{font-size:16px}.topic-tile p{font-size:13px}.editor-main,.editor-aside,.soft-panel,.text-card{padding:18px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--inline{height:185px}.media--mobile{height:290px;max-width:250px}.media--logo{height:30px}.hero-actions{gap:9px}.button-primary,.button-outline{font-size:14px;padding:8px 13px}.site-brand{max-width:43%}.site-brand .media--logo{max-width:135px}.site-brand .brand-fallback{font-size:16px}.entry-button span{display:none}.steps{gap:10px}.steps li{padding:14px}.compare th,.compare td{padding:11px}.site-footer{padding-top:30px}}
@media(max-height:440px) and (max-width:980px){.bottom-nav{position:static}.site-footer{padding-bottom:25px}.back-top{bottom:16px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}
@media(max-width:980px){body:not(.js-ready) .channel-nav{display:block;background:var(--sea)}body:not(.js-ready) .channel-inner{display:flex;flex-wrap:wrap;gap:0}body:not(.js-ready) .channel-nav a{flex:0 1 auto;font-size:13px;padding:7px 12px}body:not(.js-ready) .menu-toggle{display:none}}