:root{--bg:#F6FAFC;--surface:#fff;--tint:#EAF6FA;--tint2:#EDF4F8;--aqua:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--navy:#174B78;--title:#183A56;--text:#31485D;--muted:#687D8E;--line:#DCE9F0;--footer:#123653;--max:1180px}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;background:var(--bg);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text)}a{color:var(--navy);text-underline-offset:4px}a:hover{color:#087eaf}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--sky);outline-offset:3px}button{font:inherit;cursor:pointer}img{max-width:100%}h1,h2,h3{color:var(--title);line-height:1.36;margin-top:0}h1{font-size:clamp(2rem,3.15vw,2.3rem)}h2{font-size:1.62rem}h3{font-size:1.23rem}p{margin:0 0 1.05em}section{scroll-margin-top:28px}.wrap{width:min(calc(100% - 56px),var(--max));margin-inline:auto}.skip-link{position:absolute;top:-80px;left:10px;z-index:1500;padding:8px 16px;background:#fff}.skip-link:focus{top:10px}.sr-only{position:absolute;clip:rect(0,0,0,0);width:1px;height:1px;overflow:hidden;white-space:nowrap}.site-header{background:#fff;box-shadow:0 1px 0 var(--line)}.topbar{height:72px;display:flex;align-items:center;gap:24px}.brand{display:flex;align-items:center;text-decoration:none;flex:0 1 auto;min-width:0}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:260px;object-fit:contain}.brand-text{color:var(--navy);font-size:23px;font-weight:800;line-height:1.15;white-space:nowrap}.brand-text small{display:block;font-size:10px;letter-spacing:2px}.topbar-tagline{color:var(--muted);font-size:14px;margin:0 auto}.entry-link,.button-primary{display:inline-flex;justify-content:center;align-items:center;gap:8px;background:linear-gradient(105deg,#1787DB,#16a9cb);color:#fff!important;text-decoration:none;border-radius:9px;padding:10px 22px;font-weight:700;white-space:nowrap;min-height:42px}.entry-link:hover,.button-primary:hover{background:#174B78}.desktop-nav{background:var(--navy)}.nav-track{display:flex;align-items:stretch;justify-content:space-between;gap:12px;min-height:48px}.nav-track a{font-size:14px;color:#e9f7ff;text-decoration:none;padding:10px 8px 9px;border-bottom:3px solid transparent;white-space:nowrap}.nav-track a:hover,.nav-track a[aria-current=page]{color:#fff;border-color:var(--aqua);font-weight:700}.menu-toggle{display:none}.drawer,.drawer-overlay{visibility:hidden;pointer-events:none}.quick-band{background:#eaf6fa;border-bottom:1px solid var(--line)}.quick-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;padding-block:15px}.quick-item{display:flex;gap:10px;align-items:baseline;font-size:13px;flex-wrap:wrap}.quick-item strong{color:var(--navy)}.quick-item a{text-decoration:none;border-bottom:1px solid #aac6d5}.hero{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:35px;align-items:center;padding-block:52px}.hero h1{font-size:clamp(31px,3.5vw,42px);margin-bottom:24px}.hero p{max-width:600px}.eyebrow{display:inline-block;font-size:12px;letter-spacing:.12em;font-weight:800;color:#087f9f;text-transform:uppercase;margin-bottom:12px}.hero-actions{display:flex;gap:13px;flex-wrap:wrap;margin-top:25px}.text-button{display:inline-flex;align-items:center;padding:8px 2px;font-weight:700}.media{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;overflow:hidden;border-radius:14px;background:var(--tint);border:1px solid #e0edf3}.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--empty{background:linear-gradient(140deg,#eaf6fa,#f7fafb);position:relative}.media--empty:after{content:'';width:54px;height:54px;border-radius:50%;border:1px solid #c8dfe7;background:linear-gradient(150deg,#eef9fa,#deeff5)}.media--wide{background:#f2f8fa}.media--portrait img{max-width:75%}.section{padding-block:50px}.section--white{background:#fff}.section--tint{background:var(--tint2)}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:24px;margin-bottom:25px}.section-heading p{max-width:540px;color:var(--muted)}.section-heading h2{margin-bottom:4px}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.topic-card{background:#fff;border:1px solid var(--line);padding:20px 21px;border-radius:11px;min-width:0;text-decoration:none;transition:border-color .18s,transform .18s}.topic-card:hover{border-color:var(--sky);transform:translateY(-2px)}.topic-card h3{font-size:18px;margin:0 0 6px}.topic-card p{font-size:14px;color:var(--muted);margin:0}.topic-card span{font-size:12px;color:#1284ac;font-weight:700}.feature-grid{display:grid;grid-template-columns:2fr 1fr;gap:22px}.feature-main,.feature-side article,.panel,.knowledge-card,.archive-card{border:1px solid var(--line);background:#fff;border-radius:13px;padding:24px}.feature-main{background:var(--tint)}.feature-side{display:grid;gap:20px}.feature-side article h3{margin-bottom:10px}.split{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:center}.split--reverse .media{order:-1}.prose{max-width:780px}.prose p,.article-main p{line-height:1.84}.mini-list{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.knowledge-card{border-top:4px solid var(--aqua)}.knowledge-card h3{margin-bottom:9px}.steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;counter-reset:steps}.step{padding:15px 18px;border-top:2px solid var(--sky);background:#fff;border-radius:0 0 9px 9px}.step:before{counter-increment:steps;content:'0' counter(steps);display:block;color:#1288ab;font-weight:800;margin-bottom:8px}.step h3{font-size:17px}.editor-note{padding:20px 25px;border-left:4px solid var(--aqua);background:#fff;color:var(--muted)}.page-head{padding-block:46px 28px}.page-head h1{margin-bottom:17px}.page-head p{max-width:830px;font-size:17px}.page-head .eyebrow{margin-bottom:8px}.page-layout{display:grid;grid-template-columns:minmax(0,780px) minmax(190px,240px);gap:48px;align-items:start}.page-layout .article-main{min-width:0}.article-section{margin-bottom:40px}.article-section h2{margin-bottom:16px}.article-section h3{margin-top:22px}.lead{font-size:17px}.info-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.info-grid>*{min-width:0}.info-grid .panel{background:var(--tint2)}.info-grid h3{margin-bottom:8px}.table-scroll{max-width:100%;overflow-x:auto;margin:18px 0 28px;border:1px solid var(--line);border-radius:11px;background:#fff}table{width:100%;border-collapse:collapse;min-width:530px;text-align:left}th,td{padding:12px 15px;border-bottom:1px solid var(--line);vertical-align:top}thead{background:#e7f4f8}th{font-size:14px;color:var(--navy)}tr:last-child td{border-bottom:0}.timeline{counter-reset:timeline;display:grid;gap:12px}.timeline article{border-left:3px solid var(--aqua);padding:8px 18px;background:#fff}.timeline h3{margin-bottom:5px}.timeline p{margin:0}.aside-box{background:#eaf6fa;border:1px solid var(--line);border-radius:12px;padding:23px;position:sticky;top:24px}.aside-box h2{font-size:20px}.aside-box dl{margin:0}.aside-box dt{font-weight:800;color:var(--navy);margin-top:15px}.aside-box dd{margin:2px 0 0;font-size:14px}.matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.matrix .panel{padding:22px}.tag{display:inline-block;padding:3px 10px;background:var(--tint);color:var(--navy);font-size:12px;font-weight:700;border-radius:4px;margin-bottom:10px}.gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.gallery figure{margin:0;background:#fff;border:1px solid var(--line);border-radius:13px;overflow:hidden}.gallery figcaption{padding:18px 21px;font-size:14px}.gallery figcaption strong{display:block;font-size:18px;color:var(--title);margin-bottom:6px}.toc{display:flex;flex-wrap:wrap;gap:10px;padding:18px;background:var(--tint2);border-radius:11px;margin-bottom:30px}.toc a{background:#fff;padding:5px 12px;border-radius:5px}.faq{display:grid;gap:10px;margin-top:15px}.faq details{background:#fff;border:1px solid var(--line);border-radius:9px;padding:14px 18px}.faq summary{cursor:pointer;color:var(--navy);font-weight:700}.faq details p{margin:12px 0 2px}.related{border-top:1px solid var(--line);padding:38px 0 45px;margin-top:30px}.related-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.related-links a{background:#eaf6fa;border:1px solid var(--line);border-radius:8px;padding:13px 17px;text-decoration:none;font-weight:700}.site-footer{background:var(--footer);color:#eaf7ff;padding-top:42px}.site-footer a{color:#eaf7ff}.footer-grid{display:grid;grid-template-columns:1.2fr 1fr;gap:40px}.footer-brand{font-weight:800;font-size:23px;margin:0}.footer-brand small{font-size:11px;letter-spacing:1px}.footer-note{max-width:530px;font-size:13px;color:#c1d6e2}.site-footer h2{color:white;font-size:17px}.footer-links{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;font-size:14px}.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:15px;border-top:1px solid #335a74;padding:18px 0;font-size:12px;color:#bfdaea}.mobile-bottom{display:none}.back-top{position:fixed;right:20px;bottom:24px;background:var(--navy);border:0;border-radius:50%;color:white;width:42px;height:42px;opacity:0;pointer-events:none;transition:opacity .2s}.back-top--visible{opacity:1;pointer-events:auto}blockquote{margin:22px 0;padding:12px 24px;background:var(--tint);border-left:4px solid var(--aqua)}
@media(max-width:980px){.wrap{width:calc(100% - 44px)}.site-header{position:relative;z-index:40}.topbar{height:64px;justify-content:space-between;gap:10px}.topbar-tagline,.desktop-nav{display:none}.menu-toggle{display:flex;flex-direction:column;justify-content:center;gap:5px;align-items:center;flex:0 0 40px;width:40px;height:40px;border:1px solid var(--line);border-radius:8px;background:#fff}.menu-toggle span{display:block;width:20px;height:2px;background:var(--navy)}.brand{margin:auto}.brand img{max-height:30px;max-width:170px}.brand-text{font-size:18px}.brand-text small{font-size:8px}.entry-link{padding:8px 12px;font-size:13px;min-height:40px}.drawer-overlay{position:fixed;inset:0;background:rgba(14,41,62,.55);z-index:90;opacity:0;transition:opacity .2s;visibility:hidden;pointer-events:none}.drawer{position:fixed;top:0;bottom:0;left:0;width:min(86vw,344px);background:#fff;z-index:100;overflow:auto;transform:translateX(-100%);transition:transform .22s;visibility:hidden;pointer-events:none;box-shadow:10px 0 35px #12365333}.drawer-open{overflow:hidden}.drawer-open .drawer-overlay{visibility:visible;opacity:1;pointer-events:auto}.drawer-open .drawer{visibility:visible;transform:translateX(0);pointer-events:auto}.drawer-head{display:flex;justify-content:space-between;align-items:center;padding:19px 22px;border-bottom:1px solid var(--line)}.drawer-close{border:0;background:var(--tint);width:38px;height:38px;border-radius:8px;font-size:25px;line-height:1}.drawer-group{padding:13px 22px;border-bottom:1px solid var(--line)}.drawer-group h2{font-size:13px;letter-spacing:.04em;color:var(--muted);margin:0 0 8px}.drawer-group a{display:block;padding:9px 3px;text-decoration:none;font-weight:600}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.matrix{grid-template-columns:repeat(2,minmax(0,1fr))}.page-layout{grid-template-columns:minmax(0,1fr) 210px;gap:26px}}
@media(max-width:760px){.hero{grid-template-columns:1fr;gap:23px;padding-block:34px}.hero .media{order:-1}.feature-grid,.split,.page-layout,.footer-grid{grid-template-columns:1fr}.split--reverse .media{order:0}.aside-box{position:static}.quick-grid{grid-template-columns:1fr;gap:4px}.section{padding-block:34px}.page-head{padding-block:30px 18px}.feature-side{grid-template-columns:repeat(2,minmax(0,1fr))}.steps{grid-template-columns:repeat(2,minmax(0,1fr))}.mobile-bottom{display:flex;position:fixed;z-index:35;bottom:0;left:0;right:0;padding-bottom:env(safe-area-inset-bottom);background:#fff;border-top:1px solid var(--line);box-shadow:0 -3px 18px #183a5612}.mobile-bottom a{flex:1;text-align:center;font-size:13px;font-weight:700;text-decoration:none;padding:10px 5px}.mobile-bottom a[aria-current=page]{color:#0784b3;border-top:2px solid var(--aqua)}body{padding-bottom:calc(52px + env(safe-area-inset-bottom))}.back-top{bottom:74px}.related-links{grid-template-columns:1fr}.section-heading{display:block}.section-heading p{margin-top:7px}}
@media(max-width:640px){body{font-size:15px}.wrap{width:calc(100% - 32px)}h1{font-size:clamp(25px,7vw,29px)}h2{font-size:21px}h3{font-size:18px}.hero h1{font-size:clamp(27px,7vw,31px)}.page-head p{font-size:15px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--mobile{height:290px;max-width:250px}.topic-grid,.info-grid,.matrix,.gallery,.mini-list,.feature-side{grid-template-columns:1fr}.topic-card,.feature-main,.feature-side article,.panel,.knowledge-card,.archive-card{padding:18px}.hero-actions{gap:10px}.steps{grid-template-columns:1fr}.footer-links{grid-template-columns:repeat(2,1fr)}.brand img{max-width:130px}.entry-link{padding:6px 9px;font-size:12px}.quick-item{font-size:12px}.gallery figcaption{padding:15px}.related{padding-block:25px}.site-footer{padding-top:28px}}
@media(max-height:430px) and (max-width:760px){.mobile-bottom{position:static}body{padding-bottom:0}.back-top{bottom:15px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation-duration:.01ms!important;transition-duration:.01ms!important}}

.nojs-nav{display:flex;flex-wrap:wrap;gap:8px;padding-block:10px}.nojs-nav a{padding:4px 9px;background:#eaf6fa;border-radius:6px;font-size:14px}