:root{color-scheme:light;--bg:#fff;--fg:#09090b;--card:#fff;--muted:#71717a;--soft:#f4f4f5;--border:#e4e4e7;--brand:#555;--brand-light:#777;--radius:12px;font-family:Arial,Helvetica,sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--bg);color:var(--fg);line-height:1.6}html.dark{color-scheme:dark;--bg:hsl(220 30% 3%);--fg:#fafafa;--card:hsl(220 25% 8%);--muted:hsl(220 10% 60%);--soft:hsl(220 20% 12%);--border:hsl(220 20% 15%)}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default}button,input{color:inherit}button{background:none}img{max-width:100%;display:block}h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.15;letter-spacing:-.035em}h1{font-size:clamp(36px,6vw,72px);margin-bottom:24px}h2{font-size:32px;margin-bottom:20px}h3{font-size:18px;letter-spacing:-.015em;margin-bottom:12px}p{color:var(--muted)}:focus-visible{outline:3px solid var(--brand-light);outline-offset:4px}button,input,summary{border-radius:8px}button{border:1px solid var(--border)}.skip{position:fixed;left:12px;top:-60px;z-index:100;background:var(--card);padding:10px}.skip:focus{top:8px}.site-header{position:sticky;top:0;z-index:50;border-bottom:1px solid var(--border);background:var(--bg)}.header-inner{max-width:1440px;min-height:80px;padding:16px 24px;margin:auto;display:flex;align-items:center;gap:28px}.brand{font-weight:750;display:flex;align-items:center;gap:9px;white-space:nowrap;font-size:18px}.brand-mark{width:40px;height:40px;border-radius:8px;display:grid;place-items:center;background:var(--brand);color:white;font-size:21px}.desktop-nav{display:flex;align-items:center;gap:20px;flex:1;justify-content:center;font-size:13px}.desktop-nav>a{padding:8px}.desktop-nav a:hover,summary:hover{color:var(--brand)}.nav-group{position:relative}.nav-group summary{cursor:pointer;list-style:none;padding:8px 0}.nav-group summary:after{content:'⌄';padding-left:8px}.dropdown{position:absolute;top:38px;left:0;width:210px;padding:8px;border:1px solid var(--border);border-radius:12px;background:var(--card);box-shadow:0 12px 30px #0002}.dropdown a{display:block;padding:9px}.actions{display:flex;gap:8px;align-items:center;margin-left:auto}.icon-button{width:36px;height:36px;display:grid;place-items:center}.menu-toggle{display:none}.mobile-nav{padding:10px 24px 20px;display:grid;gap:7px;border-top:1px solid var(--border)}.mobile-nav a{padding:8px;background:var(--soft);border-radius:8px}[hidden]{display:none!important}.container{width:100%;max-width:1152px;margin:auto;padding:0 24px}.hero{text-align:center;padding:115px 0 64px}.eyebrow{display:inline-flex;border:1px solid color-mix(in srgb,var(--brand) 35%,transparent);border-radius:30px;background:color-mix(in srgb,var(--brand) 8%,transparent);padding:7px 16px;font-size:13px;color:var(--brand);margin-bottom:24px}.hero .lead{max-width:770px;margin:0 auto 32px;font-size:clamp(17px,2vw,24px);line-height:1.55}.button-row{display:flex;flex-wrap:wrap;gap:14px;justify-content:center}.button{border:1px solid var(--border);border-radius:8px;display:inline-flex;align-items:center;justify-content:center;gap:9px;padding:13px 25px;font-weight:650;background:var(--card)}.button.primary{background:var(--brand);color:#fff;border-color:var(--brand)}.button:hover{filter:brightness(.95)}.stats{display:flex;justify-content:center;gap:12px;flex-wrap:wrap;margin:35px 0 0}.stat{min-width:130px;padding:14px 24px;border:1px solid var(--border);border-radius:12px;background:var(--card)}.stat strong{display:block;font-size:25px}.stat span{font-size:12px;color:var(--muted)}.media{position:relative;aspect-ratio:16/9;background:linear-gradient(135deg,var(--soft),var(--card));border:1px solid var(--border);border-radius:16px;overflow:hidden;max-width:1024px;margin:auto;display:grid;place-items:center}.media img{position:absolute;width:100%;height:100%;object-fit:cover}.media .play{position:relative;width:68px;height:68px;display:grid;place-items:center;border-radius:50%;background:var(--brand);color:#fff;font-size:26px;box-shadow:0 0 0 14px #ffffff22}.media small{position:absolute;bottom:12px;right:12px;background:#000a;color:white;padding:3px 8px;border-radius:5px}.media-fallback{position:absolute;font-size:clamp(20px,4vw,48px);opacity:.35;font-weight:bold;letter-spacing:.08em}.section{padding:64px 0}.section.alt{background:color-mix(in srgb,var(--soft) 35%,var(--bg))}.section-intro{max-width:700px}.center{text-align:center;margin-left:auto;margin-right:auto}.grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px}.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.card{min-width:0;display:block;border:1px solid var(--border);border-radius:var(--radius);background:var(--card);padding:24px;transition:border-color .15s,transform .15s}.card p{font-size:14px;line-height:1.75;margin-bottom:0}.card-link:hover{border-color:var(--brand-light);transform:translateY(-2px)}.tile-icon{height:42px;width:42px;border-radius:10px;display:grid;place-items:center;color:var(--brand);background:var(--soft);margin-bottom:20px;font-weight:700}.card-link .arrow{color:var(--brand);display:block;margin-top:16px;font-size:13px}.meta{font-size:12px;color:var(--muted);display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:12px}.badge{background:var(--brand);color:#fff;padding:3px 8px;border-radius:5px;font-size:11px;letter-spacing:0}.code-row{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:18px 0;border-bottom:1px solid var(--border)}.code-row code{font-weight:700;font-size:17px;overflow-wrap:anywhere}.code-row small{display:block;color:var(--muted)}.copy{padding:8px 12px;background:var(--soft);white-space:nowrap}.notice{padding:18px 22px;border:1px solid color-mix(in srgb,var(--brand) 30%,var(--border));background:color-mix(in srgb,var(--brand) 5%,var(--bg));border-radius:12px;color:var(--muted);font-size:14px;margin:22px 0}.table-wrap{max-width:100%;overflow-x:auto;border:1px solid var(--border);border-radius:12px}table{width:100%;border-collapse:collapse;text-align:left;font-size:14px}th,td{padding:14px 18px;border-bottom:1px solid var(--border)}th{background:var(--soft)}tr:last-child td{border-bottom:0}.faq details{border-bottom:1px solid var(--border);padding:18px 0}.faq summary{font-weight:650;cursor:pointer}.faq p{margin:15px 0 0;font-size:14px}.site-footer{margin-top:50px;padding:40px 24px;border-top:1px solid var(--border);font-size:13px}.footer-inner{max-width:1152px;margin:auto;display:flex;justify-content:space-between;gap:30px;flex-wrap:wrap}.footer-inner nav{display:flex;gap:20px;flex-wrap:wrap}.footer-inner p{margin-top:12px;max-width:500px}.demo-note{font-size:11px;color:var(--muted)}.sidebar-theme .header-inner{max-width:1280px;gap:16px}.sidebar-theme .desktop-nav{gap:0}.sidebar-theme .brand{font-size:16px}.sidebar-theme .brand-mark{width:32px;height:32px;font-size:16px}.sidebar-theme .header-inner{min-height:72px}.sidebar-theme .desktop-nav>a{padding:8px 10px}.sidebar-shell{max-width:1280px;padding:40px 32px;margin:auto;display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:40px}.sidebar-content{min-width:0}.sidebar-content>section{margin-bottom:64px}.sidebar-theme .hero{padding:24px 0 0}.sidebar-theme .hero h1{font-size:clamp(36px,4.2vw,60px);font-weight:800;margin:0}.title-row{display:flex;align-items:center;justify-content:center;gap:8px;margin-bottom:24px}.title-row .badge{max-width:120px;font-size:11px;line-height:1.4}.sidebar-theme .hero .lead{font-size:16px;line-height:1.65;margin:20px 0 0}.sidebar-theme .stats{gap:6px;margin-top:16px}.sidebar-theme .stat{min-width:0;padding:3px 10px;border:0;background:var(--soft);border-radius:20px;line-height:1.5}.sidebar-theme .stat strong,.sidebar-theme .stat span{font-size:11px;display:inline;font-weight:500}.sidebar-theme .stat strong{margin-right:4px}.sidebar{align-self:start;position:sticky;top:96px;max-height:calc(100vh - 120px);overflow-y:auto}.sidebar .card{padding:20px;margin-bottom:24px}.sidebar h3{font-size:16px}.side-link{display:flex;align-items:center;gap:12px;padding:10px 0;font-size:14px}.side-link span:first-child{height:30px;width:30px;background:var(--soft);border-radius:8px;display:grid;place-items:center;color:var(--brand)}.side-link small{margin-left:auto;color:var(--muted)}.journey-layout{display:grid;grid-template-columns:.85fr 1.15fr;gap:32px}.update-panel{padding:20px}.updates{max-height:500px;overflow-y:auto;display:grid;gap:12px}.update-item{display:block;border:1px solid var(--border);padding:16px;border-radius:12px;background:var(--bg)}.update-item h3{font-size:15px;line-height:1.5;margin-bottom:0}.update-item .meta{justify-content:space-between;gap:8px}.update-panel>.button{width:100%;padding:9px;margin-top:20px;font-size:13px}.section-kicker{color:var(--brand);font-size:13px;font-weight:650;margin:0 0 6px}.journey-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.journey-grid .card{padding:20px;border-radius:16px}.number{width:36px;height:36px;border-radius:50%;display:grid;place-items:center;background:var(--brand);color:white;font-weight:bold;margin-bottom:16px}.journey-grid p{font-size:13px}.scroller{display:flex;gap:16px;overflow:auto;padding:8px 0 18px;scroll-snap-type:x mandatory}.scroller .card{width:270px;flex:0 0 270px;scroll-snap-align:start}.about-panel{display:grid;grid-template-columns:1.1fr .9fr;gap:25px;background:var(--card);padding:28px;border:1px solid var(--border);border-radius:24px}.facts{margin:0}.facts>div{padding:12px 0;border-bottom:1px solid var(--border)}dt{font-size:12px;color:var(--muted)}dd{margin:0;font-weight:600;font-size:14px}.module-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.cta{padding:36px;text-align:center;border-radius:24px;border:1px solid var(--border);background:linear-gradient(135deg,var(--soft),var(--card))}.category-head{padding:55px 0 25px}.category-head h1{font-size:48px}.breadcrumb{display:flex;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:13px;margin-bottom:25px}.filters{display:flex;gap:12px;margin:20px 0 30px;flex-wrap:wrap}input[type=search]{min-width:0;flex:1;padding:13px 16px;background:var(--card);border:1px solid var(--border)}.filters select{padding:10px;border:1px solid var(--border);background:var(--card);color:var(--fg)}.article-head{max-width:920px;margin:0 auto;padding:48px 24px 24px;text-align:center}.article-head h1{font-size:clamp(32px,4.5vw,50px)}.article-head p{font-size:18px}.article-head .meta,.article-head .breadcrumb{justify-content:center}.article-shell{max-width:1136px;padding:16px 24px;margin:auto;display:grid;grid-template-columns:minmax(0,1fr);gap:32px}.article-main{min-width:0;max-width:896px;margin:auto;width:100%}.article-main section{margin:40px 0}.article-main p,.article-main li{font-size:16px;line-height:1.9}.article-main h2{font-size:29px;scroll-margin-top:100px}.article-main h3{margin-top:30px}.article-main ul,.article-main ol{padding-left:24px;color:var(--muted)}.toc{border:1px solid var(--border);background:var(--card);border-radius:16px;padding:20px}.toc summary{cursor:pointer;font-weight:bold}.toc nav{display:grid;gap:8px;padding-top:12px;font-size:14px;color:var(--muted)}.ad-rail{display:none;width:192px;padding-right:32px}.ad-placeholder{width:160px;height:600px;border:1px dashed var(--border);display:grid;place-items:center;text-align:center;font-size:12px;color:var(--muted);background:var(--soft);position:sticky;top:100px}.sidebar-theme .article-head{text-align:left}.sidebar-theme .article-head .meta,.sidebar-theme .article-head .breadcrumb{justify-content:flex-start}.empty{text-align:center;padding:48px;border:1px dashed var(--border);border-radius:12px}.search-dialog{width:min(600px,calc(100% - 32px));border:1px solid var(--border);border-radius:18px;background:var(--card);color:var(--fg);padding:24px}.search-dialog::backdrop{background:#0009}.dialog-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.dialog-head h2{margin:0;font-size:24px}.search-dialog input{width:100%}.search-results{display:grid;gap:10px;max-height:50vh;overflow:auto;margin-top:16px}.search-results a{padding:12px;background:var(--soft);border-radius:8px}.back-top{position:fixed;bottom:24px;right:24px;border:1px solid var(--border);background:var(--card);width:40px;height:40px;border-radius:50%;z-index:20}.status{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);padding:12px 22px;background:var(--fg);color:var(--bg);border-radius:10px;z-index:90;max-width:90vw;font-size:13px}
@media(min-width:1280px) and (min-height:700px){.article-shell.preview-ads{grid-template-columns:192px minmax(0,1fr)}.preview-ads .ad-rail{display:block}}
@media(max-width:1150px){.desktop-nav{gap:6px}.header-inner{gap:12px;padding:16px}.sidebar-theme .desktop-nav>a{padding:8px 5px;font-size:12px}.sidebar-shell{gap:24px;padding:32px 24px}.journey-layout{grid-template-columns:1fr}.grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:1023px){.sidebar-shell{grid-template-columns:minmax(0,1fr)}.sidebar{position:static;max-height:none;display:grid;grid-template-columns:1fr 1fr;gap:20px}.journey-layout{grid-template-columns:.85fr 1.15fr}.desktop-nav{display:none}.menu-toggle{display:grid}.hero{padding-top:80px}.sidebar-theme .hero h1{font-size:54px}.header-inner{min-height:72px}}
@media(max-width:639px){.container{padding:0 18px}.hero{padding:60px 0 35px}.hero h1{font-size:42px}.hero .lead{font-size:17px}.section{padding:40px 0}h2{font-size:27px}.grid,.grid.two,.module-grid,.journey-layout,.about-panel{grid-template-columns:minmax(0,1fr)}.stats{gap:8px}.stat{padding:10px;min-width:calc(50% - 8px)}.card{padding:20px}.button-row{flex-direction:column}.button-row .button{width:100%}.sidebar-shell{padding:26px 16px;gap:20px}.sidebar-theme .hero h1{font-size:38px}.title-row{flex-direction:column;gap:16px}.title-row .badge{max-width:none}.sidebar-content>section{margin-bottom:40px}.sidebar{display:block}.journey-grid{gap:10px}.journey-grid .card{padding:16px}.journey-grid h3{font-size:16px}.sidebar-theme .stat{min-width:0}.article-head{padding:32px 18px 15px}.article-head h1{font-size:34px}.article-shell{padding:0 18px}.article-main h2{font-size:26px}.header-inner{padding:14px;gap:6px}.brand{font-size:16px}.brand-mark{width:32px;height:32px;font-size:17px}.sidebar-theme .brand{font-size:14px}.actions{gap:5px}.icon-button{width:32px;height:32px}.language{display:none}.category-head h1{font-size:38px}.media .play{width:52px;height:52px}.cta{padding:25px}.footer-inner{display:block}.footer-inner nav{margin-top:20px}.filters{flex-direction:column}.about-panel{padding:22px}th,td{padding:10px}.code-row{align-items:flex-start}.ad-rail{display:none}}
.sidebar-theme .category-page{max-width:944px}.landing-theme .category-head{text-align:center}.landing-theme .category-head .breadcrumb{justify-content:center}.category-intro h2{font-size:24px}.category-intro h3{margin-top:22px}.sidebar-theme .category-head{padding-top:40px}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}

/* Local advertisement preview only. Dimensions and visibility stay unchanged. */
.ad-placeholder{border:3px dashed #c2410c;border-radius:12px;background:repeating-linear-gradient(135deg,#fff7ed 0,#fff7ed 16px,#ffedd5 16px,#ffedd5 32px);color:#7c2d12;box-shadow:0 0 0 5px #fb923c30;display:flex;flex-direction:column;justify-content:space-between;align-items:center;padding:16px 10px;gap:16px;font-family:Arial,"Microsoft YaHei",sans-serif}
.ad-preview-badge{display:block;background:#9a3412;color:#fff;border-radius:6px;padding:5px 9px;font-size:13px;font-weight:700;letter-spacing:.04em}
.ad-preview-center{display:flex;flex-direction:column;align-items:center;gap:12px}.ad-preview-center strong{font-size:22px;line-height:1.2;white-space:nowrap;color:#7c2d12}.ad-preview-center>span:not(.ad-preview-icon){font-size:13px;font-weight:700}.ad-preview-center small{font-size:12px;color:#9a3412}
.ad-preview-icon{width:64px;height:64px;border:2px solid #c2410c;border-radius:12px;display:grid;place-items:center;font-size:25px;font-weight:800;background:#fff7ed}.ad-preview-footer{font-size:11px;line-height:1.8;font-weight:600;border-top:1px solid #fb923c;padding-top:12px;width:100%}
.ad-placement{container-type:inline-size;width:100%;min-width:0;margin:28px 0 40px;text-align:center;font-family:Arial,"Microsoft YaHei",sans-serif}
.ad-slot-caption{display:flex;justify-content:center;align-items:center;flex-wrap:wrap;gap:8px;margin-bottom:10px;font-size:12px;color:#9a3412}.ad-slot-caption b{background:#9a3412;color:#fff;padding:3px 9px;border-radius:5px}.ad-slot-caption>span{background:#fff7ed;color:#7c2d12;padding:3px 7px;border-radius:5px}
.ad-slot-frame{box-sizing:border-box;max-width:100%;margin:0 auto;border:3px dashed #c2410c;border-radius:10px;background:repeating-linear-gradient(135deg,#fff7ed 0,#fff7ed 16px,#ffedd5 16px,#ffedd5 32px);color:#7c2d12;display:flex;align-items:center;justify-content:center;gap:14px;box-shadow:0 0 0 3px #fb923c20}
.ad-slot-frame--banner{width:100%;height:50px}.ad-slot-frame--rectangle{width:300px;height:250px;flex-direction:column}.ad-slot-frame strong{font-size:18px;line-height:1.2}.ad-slot-frame--rectangle strong{font-size:25px}.ad-slot-symbol{font-size:14px;font-weight:800;border:1px solid #c2410c;border-radius:6px;padding:2px 8px;background:#fff7ed}.ad-slot-frame--rectangle .ad-slot-symbol{font-size:26px;padding:10px 16px}.ad-slot-note{display:block;margin-top:9px;font-size:11px;color:#9a3412;background:#fff7ed;border-radius:4px;width:max-content;max-width:100%;padding:2px 7px;margin-left:auto;margin-right:auto}
.ad-size-wide,.ad-size-mobile{display:none}.ad-size-fluid{display:block}
@container(min-width:320px){.ad-slot-frame--banner{width:320px}.ad-size-mobile{display:block}.ad-size-fluid{display:none}}
@container(min-width:728px){.ad-slot-frame--banner{width:728px;height:90px}.ad-size-wide{display:block}.ad-size-mobile{display:none}.ad-slot-frame--banner strong{font-size:25px}}
@media(max-width:1023px){.ad-placement--homeSidebar{display:none}}

.brand{white-space:normal;min-width:0}.brand-mark{flex-shrink:0}.icon-button{width:44px;height:44px;flex-shrink:0}.actions{flex-shrink:0}figure{margin:24px 0}figure img{width:100%;height:auto;border-radius:12px}figcaption{font-size:13px;color:var(--muted);padding-top:10px}.article-main p,.article-main li{color:var(--fg)}.hero.container{padding-left:24px;padding-right:24px}.media img{object-fit:contain}p,li,h1,h2,h3{overflow-wrap:break-word}@media(max-width:639px){.header-inner{padding:10px;gap:6px}.brand{font-size:14px;gap:6px}.brand-mark{width:28px;height:32px;font-size:16px}.actions{gap:3px}.icon-button{width:44px;height:44px}.hero.container{padding-left:18px;padding-right:18px}.article-main p,.article-main li{line-height:1.75}.back-top{width:44px;height:44px}}

.section.container{padding-left:24px;padding-right:24px}@media(max-width:639px){.section.container{padding-left:18px;padding-right:18px}}