*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:#080A0D;color:#C7CDD5;font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif}a{color:#a5c8ff;text-decoration:none}a:hover{color:#8ED8FF}button{font:inherit}img{max-width:100%;height:auto}p{margin:0 0 17px}h1,h2,h3{color:#F5F7FA;line-height:1.38;letter-spacing:.01em}h1{font-size:34px;margin:12px 0 20px}h2{font-size:26px;margin:0 0 17px}h3{font-size:19px;margin:0 0 10px}.wrap{max-width:1200px;margin:auto;padding-left:24px;padding-right:24px}.skip-link{position:absolute;z-index:200;top:-70px;left:10px;background:#5C7CFA;color:white;padding:8px}.skip-link:focus{top:8px}:focus-visible{outline:2px solid #8ED8FF;outline-offset:3px}.site-header{background:rgba(8,10,13,.96);border-bottom:1px solid rgba(255,255,255,.09)}.topbar{height:76px;display:flex;align-items:center;gap:20px}.brand{flex:0 0 215px;display:flex;align-items:center;gap:10px;min-width:0;color:#f5f7fa}.brand-word{font-size:10px;white-space:nowrap;color:#9098a3;letter-spacing:.08em}.brand-logo,.drawer-logo,.footer-logo{border:0;background:transparent;margin:0;border-radius:0;flex-shrink:0}.brand-logo img{max-height:36px;width:auto}.brand-logo .media-placeholder{width:76px;height:34px}.primary-nav{display:flex;justify-content:center;align-items:center;flex:1;gap:clamp(12px,1.5vw,22px);min-width:0}.primary-nav a{font-size:14px;color:#c7cdd5;white-space:nowrap;padding:23px 0 20px;border-bottom:2px solid transparent}.primary-nav a.active{color:#6EA8FF;border-color:#6EA8FF}.entry-link{white-space:nowrap;background:#5C7CFA;border-radius:99px;color:#fff;font-weight:700;font-size:14px;padding:8px 19px;line-height:26px}.entry-link:hover{color:#fff;background:#7390FF}.menu-toggle{display:none;cursor:pointer;background:transparent;border:1px solid #37414c;border-radius:10px;width:40px;height:40px;padding:10px;flex-direction:column;justify-content:space-around}.menu-toggle span{display:block;height:2px;width:100%;background:#f5f7fa}.quick-strip{background:#10141A;border-bottom:1px solid #222a34}.quick-inner{display:flex;align-items:center;gap:clamp(15px,3vw,30px);min-height:44px;overflow-x:auto;scrollbar-width:none;white-space:nowrap}.quick-inner::-webkit-scrollbar{display:none}.quick-inner a{font-size:13px;color:#c7cdd5}.quick-inner a:hover{color:#8ed8ff}.quick-label{font-size:12px;color:#7d8794;border-right:1px solid #313945;padding-right:18px}.page-content{min-height:45vh;padding-top:28px;padding-bottom:65px}.breadcrumbs{display:flex;align-items:center;flex-wrap:wrap;gap:12px;font-size:13px;color:#9098A3;margin:2px 0 28px}.breadcrumbs a{color:#98a2af}.eyebrow{display:block;color:#8ed8ff;letter-spacing:.15em;font-size:12px;font-weight:bold}.lead{font-size:17px;line-height:1.85;color:#cbd3dd;max-width:840px}.page-intro{margin-bottom:35px;max-width:900px}.page-intro h1{max-width:850px}.article-shell{display:grid;grid-template-columns:minmax(0,1fr) 210px;gap:54px;align-items:start}.article-main{min-width:0;max-width:820px}.article-main section{margin-bottom:36px;padding-bottom:22px;border-bottom:1px solid rgba(255,255,255,.09)}.article-main section h2{font-size:24px}.article-main section p{max-width:760px}.article-side{position:sticky;top:22px;background:#12161c;padding:20px;border:1px solid #26303b;border-radius:12px}.article-side h2{font-size:16px}.article-side a{display:block;padding:7px 0;color:#aeb7c2;font-size:13px;border-bottom:1px solid #252c34}.article-side a:last-child{border:0}.index-number{font-size:13px;letter-spacing:.1em;color:#6EA8FF;font-weight:700}.section-heading{display:flex;gap:15px;align-items:baseline}.section-heading .index-number{min-width:28px}.related{margin-top:45px;padding:25px 0;border-top:1px solid #343b45}.related h2{font-size:22px}.related-links{display:flex;flex-wrap:wrap;gap:11px}.related-links a{border:1px solid #36404d;background:#12161c;border-radius:999px;padding:7px 16px;font-size:14px}.reading-note{padding:18px 24px;border-left:3px solid #5c7cfa;background:#12161c;color:#aeb8c4;margin:20px 0 40px}.reading-note strong{color:#fff}.media-frame{margin:0;min-width:0;max-width:100%;background:#0d1015;border:1px solid rgba(255,255,255,.09);border-radius:13px;padding:9px;overflow:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center}.media-frame img{display:block;max-width:100%;width:auto;height:auto;max-height:100%;object-fit:contain;object-position:center center}.media-frame figcaption{font-size:13px;color:#99a4b0;line-height:1.6;padding:10px 4px 2px;align-self:stretch}.media-placeholder{min-height:135px;width:100%;background:linear-gradient(135deg,#121822,#1b2430 52%,#101419);border-radius:8px}.figure-hero{height:300px}.figure-hero img{max-height:280px}.figure-hero .media-placeholder{height:100%}.figure-topic{height:245px}.figure-topic img{max-height:220px}.figure-topic .media-placeholder{height:100%}.figure-small{height:180px}.figure-small img{max-height:145px}.figure-small .media-placeholder{min-height:110px;flex:1}.figure-phone{width:270px;max-width:100%;height:340px}.figure-phone img{max-height:310px}.figure-phone .media-placeholder{height:100%}.figure-gif{height:175px}.figure-gif img{max-height:145px}.figure-gallery{min-height:220px}.figure-gallery img{max-height:245px}.figure-gallery .media-placeholder{height:190px}.hero-layout{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(0,1fr);gap:38px;align-items:center;margin-bottom:52px}.hero-layout .hero-copy{min-width:0}.hero-copy h1{font-size:41px}.hero-copy .lead{font-size:16px}.hero-actions{display:flex;gap:20px;margin-top:24px;flex-wrap:wrap}.hero-actions a{border-bottom:1px solid #6ea8ff;padding:4px 0}.chapter-head{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:18px}.chapter-head small{color:#8ed8ff;letter-spacing:.14em}.home-section{margin:46px 0 56px}.home-section>p{max-width:820px}.intro-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.intro-grid article{padding:23px;border:1px solid #2c3540;border-radius:13px;background:#12161c}.intro-grid h3{margin-bottom:8px}.intro-grid p{font-size:15px;margin:0}.split-feature{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,.75fr);gap:35px}.feature-aside{border-left:1px solid #344050;padding-left:26px}.feature-aside article{margin-bottom:22px}.feature-aside span{display:block;color:#6ea8ff;font-size:12px}.duo{display:grid;grid-template-columns:1fr 1fr;gap:35px}.duo>article{border-top:2px solid #343f4e;padding-top:20px}.home-visuals{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:17px}.visual-card{min-width:0}.visual-card p{font-size:14px;margin:10px 0 0}.photo-text{display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:35px;align-items:center}.photo-text>div{min-width:0}.topic-index{list-style:none;counter-reset:topics;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:0 32px}.topic-index li{counter-increment:topics;border-bottom:1px solid #28313b;padding:14px 0}.topic-index li:before{content:'0' counter(topics);font-size:12px;color:#6ea8ff;display:inline-block;width:38px}.topic-index a{font-weight:bold}.topic-index p{font-size:14px;margin:5px 0 0 38px}.ethical-band{border-top:1px solid #343d48;padding-top:25px}.page-design-note{font-size:13px;color:#9098a3;margin-top:40px}.content-illustration{margin:24px 0 30px;max-width:800px}.illustration-three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin:25px 0 35px}.illustration-three figure{height:210px}.illustration-three figure img{max-height:165px}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.gallery-grid figure img{max-height:240px}.gallery-grid figure{height:300px}.gallery-grid figure:first-child{grid-column:span 2;height:340px}.gallery-grid figure:first-child img{max-height:285px}.gallery-grid figure figcaption{font-size:14px}.gallery-ten{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.gallery-ten article{border:1px solid #303944;border-radius:12px;padding:13px;background:#12161c;min-width:0}.gallery-ten .media-frame{height:190px}.gallery-ten .media-frame img{max-height:163px}.gallery-ten h3{font-size:17px;margin:14px 0 7px}.gallery-ten p{font-size:14px;line-height:1.8}.group-title{margin:35px 0 18px;border-bottom:1px solid #2b3540;padding-bottom:12px}.knowledge-list{display:grid;grid-template-columns:1fr 1fr;gap:18px}.knowledge-list article{padding:23px;background:#12161c;border:1px solid #303944;border-radius:12px}.knowledge-list article h2{font-size:20px}.knowledge-list article p{font-size:15px}.topic-map{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.topic-map section{padding:24px;border:1px solid #2e3742;border-radius:12px;background:#12161c}.topic-map section h2{font-size:21px}.map-links{display:flex;gap:8px;flex-wrap:wrap;margin-top:15px}.map-links a{font-size:13px;border-bottom:1px solid #54749a}.comparison-table{width:100%;border-collapse:collapse;margin:25px 0 35px;font-size:14px}.comparison-table td,.comparison-table th{border:1px solid #313b48;text-align:left;padding:11px 14px;vertical-align:top}.comparison-table th{background:#1b2430;color:#fff}.question-list details{border:1px solid #313b48;border-radius:10px;background:#12161c;margin-bottom:10px;padding:0 18px}.question-list summary{color:#f5f7fa;font-weight:bold;cursor:pointer;padding:15px 0}.question-list details p{padding:0 0 12px}.steps .article-main section{padding-left:24px;border-left:2px solid #313e50;border-bottom:0}.steps .index-number{font-size:20px}.timeline .article-main section{border-bottom:0;border-left:1px solid #485873;padding:0 0 20px 25px}.timeline .article-main h2{position:relative}.timeline .article-main h2:before{content:'';position:absolute;left:-31px;top:10px;width:11px;height:11px;border-radius:50%;background:#6ea8ff}.focus .article-main section:first-child{padding:25px;background:#12161c;border-radius:13px}.solo .article-shell{grid-template-columns:minmax(0,820px)}.solo .article-side{display:none}.site-footer{background:#050608;border-top:1px solid #242b35;padding:40px 0 16px}.footer-grid{display:grid;grid-template-columns:1.2fr 1fr 1fr;gap:50px}.footer-grid h2{font-size:16px}.footer-brand p{color:#9098a3;font-size:13px}.footer-logo img{max-height:33px}.footer-logo .media-placeholder{max-width:90px;min-height:30px}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:5px 15px}.footer-links a{font-size:13px;color:#a8b1be}.footer-bottom{border-top:1px solid #1d242d;margin-top:33px;padding-top:18px;display:flex;justify-content:space-between;gap:30px;font-size:12px;color:#838d99}.back-top{position:fixed;bottom:22px;right:22px;background:#1b2634;border:1px solid #55677f;border-radius:50%;color:#fff;width:42px;height:42px;cursor:pointer;opacity:0;pointer-events:none;transition:opacity .2s}.back-top.visible{opacity:1;pointer-events:auto}.drawer-mask{position:fixed;inset:0;background:rgba(0,0,0,.68);z-index:50;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .2s,visibility .2s}.drawer{position:fixed;z-index:51;inset:0 auto 0 0;width:min(390px,86vw);background:#0d1015;transform:translateX(-100%);visibility:hidden;pointer-events:none;transition:transform .25s,visibility .25s;display:flex;flex-direction:column;box-shadow:10px 0 40px #0009}.drawer.is-open{transform:translateX(0);visibility:visible;pointer-events:auto}.drawer-mask.is-open{opacity:1;visibility:visible;pointer-events:auto}.drawer-head{display:flex;justify-content:space-between;align-items:center;padding:18px 20px;border-bottom:1px solid #343a44;min-height:76px}.drawer-logo img{max-height:33px}.drawer-close{border:0;background:transparent;color:#fff;font-size:30px;cursor:pointer;line-height:1}.drawer-scroll{padding:15px 22px 50px;overflow-y:auto}.drawer-scroll section{border-bottom:1px solid #27303a;padding:12px 0 18px}.drawer-scroll h2{font-size:14px;color:#8ed8ff}.drawer-home{display:block;font-weight:bold;margin:10px 0}.drawer-links{display:grid;grid-template-columns:1fr 1fr;gap:8px 16px}.drawer-links a{color:#bfc6cf;font-size:14px;padding:4px 0}
@media(max-width:1100px){.primary-nav{gap:11px}.brand{flex-basis:172px}.brand-word{display:none}}
@media(max-width:979px){.wrap{padding-left:20px;padding-right:20px}.topbar{height:64px;justify-content:space-between;position:relative}.menu-toggle{display:flex}.primary-nav{display:none}.brand{position:absolute;left:50%;transform:translateX(-50%);flex:0 0 auto;width:auto;max-width:110px;justify-content:center}.brand-logo img{max-height:28px}.entry-link{font-size:12px;padding:6px 11px;line-height:26px}.quick-label{display:none}.quick-inner{gap:22px;min-height:43px}.quick-inner a{flex:0 0 auto}.article-shell{grid-template-columns:minmax(0,1fr) 175px;gap:25px}.hero-copy h1{font-size:35px}.footer-grid{gap:25px}}
@media(max-width:767px){.wrap{padding-left:16px;padding-right:16px}.page-content{padding-bottom:40px}.article-shell,.hero-layout,.split-feature,.duo,.photo-text{grid-template-columns:minmax(0,1fr)}.article-side{position:static;order:-1;display:grid;grid-template-columns:1fr 1fr;gap:3px 12px}.article-side h2{grid-column:span 2}.article-side a{font-size:12px}.hero-layout{gap:18px}.hero-layout .media-frame{order:-1}.hero-copy h1{font-size:30px}.figure-hero{height:220px}.figure-hero img{max-height:197px}.figure-topic{height:200px}.figure-topic img{max-height:175px}.figure-small{height:155px}.figure-small img{max-height:120px}.figure-phone{width:220px;height:330px;margin:auto}.figure-gif{height:145px}.figure-gif img{max-height:115px}.home-section{margin:32px 0 40px}.intro-grid{grid-template-columns:1fr}.chapter-head{align-items:flex-start}.home-visuals{grid-template-columns:1fr 1fr}.feature-aside{padding-left:18px}.topic-index{grid-template-columns:1fr}.gallery-ten{grid-template-columns:repeat(2,minmax(0,1fr))}.gallery-grid{grid-template-columns:1fr}.gallery-grid figure:first-child{grid-column:auto;height:270px}.gallery-grid figure{height:260px}.illustration-three{grid-template-columns:1fr 1fr}.illustration-three figure{height:175px}.knowledge-list,.topic-map{grid-template-columns:1fr}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:span 2}.footer-bottom{flex-direction:column;gap:7px}h1{font-size:27px}h2,.article-main section h2{font-size:21px}h3{font-size:18px}.lead{font-size:16px}.page-intro{margin-bottom:24px}}
@media(max-width:390px){.topbar{gap:4px}.brand{max-width:95px}.brand-logo img{max-height:27px}.entry-link{padding:6px 9px}.home-visuals,.illustration-three{grid-template-columns:1fr}.gallery-ten{grid-template-columns:1fr}.gallery-ten .media-frame{height:185px}.footer-links{grid-template-columns:1fr}.article-side{grid-template-columns:1fr}.article-side h2{grid-column:auto}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}