:root{--ink:#12130f;--cream:#f3efe5;--paper:#faf8f2;--red:#cf3828;--lime:#c8f560;--muted:#706f68;--line:rgba(18,19,15,.15)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:110px}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Avenir Next",Avenir,"PingFang SC","Microsoft YaHei",sans-serif}a{color:inherit}button,input{font:inherit}button,a{-webkit-tap-highlight-color:transparent}button{cursor:pointer}a:focus-visible,button:focus-visible,input:focus-visible{outline:3px solid var(--red);outline-offset:4px}[hidden]{display:none!important}[data-lang=en] .zh,[data-lang=zh] .en{display:none}
.nav-shell{position:fixed;z-index:50;top:14px;left:50%;display:flex;align-items:center;justify-content:space-between;gap:12px;width:min(1440px,calc(100% - 28px));height:58px;padding:8px 10px 8px 12px;border:1px solid var(--line);border-radius:16px;background:rgba(250,248,242,.94);backdrop-filter:blur(18px);box-shadow:0 14px 40px #12130f12;transform:translateX(-50%)}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:800;letter-spacing:-.03em}.brand img{width:36px;height:36px;border-radius:10px}.brand small{display:block;color:var(--muted);font-size:10px;letter-spacing:.12em;text-transform:uppercase}nav{display:flex;align-items:center;gap:3px}nav a,.lang{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:9px 11px;border:0;border-radius:9px;color:#55564f;background:none;text-decoration:none;font-size:14px;font-weight:800}nav a:hover,.lang:hover{background:#ebe7dd}nav a[aria-current=page]{color:var(--ink);background:#ebe7dd}.nav-cta{color:white;background:var(--ink)}nav .nav-cta:hover{background:#30312b}.skip-link{position:fixed;z-index:100;top:8px;left:16px;padding:12px 18px;background:var(--ink);color:white;transform:translateY(-160%)}.skip-link:focus{transform:none}
.wrap{width:min(1200px,calc(100% - 80px));margin-inline:auto}.help-hero{padding:132px 0 56px;background:var(--cream);border-bottom:1px solid var(--line)}.eyebrow{margin:0 0 24px;color:var(--red);font-size:12px;font-weight:800;letter-spacing:.18em;text-transform:uppercase}.hero-grid{display:grid;grid-template-columns:1.45fr 1fr;align-items:end;gap:64px}h1{margin:0;font-size:clamp(36px,4.5vw,64px);line-height:1.17;letter-spacing:-.055em}h1 em{font-style:normal;color:var(--red)}.lead{max-width:650px;margin:22px 0 0;color:var(--muted);font-size:17px;line-height:1.8}.search-box{display:flex;align-items:center;gap:14px;padding:16px 18px;border:1px solid var(--ink);border-radius:12px;background:var(--paper)}.search-box svg{width:22px;flex-shrink:0}.search-box input{width:100%;min-width:0;border:0;background:none;color:var(--ink);font-size:15px;line-height:1.6}.search-box input:focus-visible{outline-offset:6px}.search-hint{margin:12px 0 0;color:var(--muted);font-size:12px;line-height:1.7}.help-main{padding-block:40px 76px}.topic-bar{display:flex;justify-content:space-between;align-items:center;gap:20px;padding-bottom:28px;border-bottom:1px solid var(--line)}.filters{display:flex;gap:8px;flex-wrap:wrap}.filter{padding:11px 16px;border:1px solid var(--line);border-radius:100px;background:transparent;color:#56574f;font-size:14px;font-weight:700}.filter:hover{border-color:var(--ink)}.filter[aria-pressed=true]{background:var(--ink);border-color:var(--ink);color:var(--lime)}.result-count{flex-shrink:0;color:var(--muted);font-size:13px}.question-list{list-style:none;padding:0;margin:0}.question-link{display:grid;grid-template-columns:54px 1fr auto;gap:22px;align-items:center;padding:30px 8px;border-bottom:1px solid var(--line);text-decoration:none;transition:background .18s,padding .18s}.question-link:hover{padding-inline:18px;background:var(--cream)}.question-no{align-self:start;margin-top:4px;color:#8a897f;font-size:15px;font-variant-numeric:tabular-nums}.question-label{display:block;margin-bottom:9px;color:var(--red);font-size:11px;font-weight:800;letter-spacing:.06em}.question-title{margin:0;font-size:clamp(18px,2vw,23px);line-height:1.45;letter-spacing:-.025em}.question-summary{margin:9px 0 0;color:var(--muted);font-size:14px;line-height:1.7}.question-meta{display:flex;align-items:center;gap:20px;margin-left:16px;color:var(--muted);font-size:12px}.arrow{display:grid;place-items:center;width:42px;height:42px;border:1px solid var(--line);border-radius:50%;color:var(--ink);font-size:22px}.question-link:hover .arrow{background:var(--lime);border-color:var(--lime)}.empty-state{padding:64px 20px;text-align:center}.empty-state h2{font-size:25px}.empty-state p{color:var(--muted);line-height:1.7}.text-button{padding:10px 0;border:0;border-bottom:1px solid var(--ink);background:none;font-weight:700}.support-strip{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-top:52px;padding:30px 34px;border-radius:16px;background:var(--lime)}.support-strip h2{margin:0 0 9px;font-size:22px;letter-spacing:-.025em}.support-strip p{margin:0;color:#485434;font-size:14px;line-height:1.7}.support-strip a{flex-shrink:0;font-size:14px;font-weight:800;text-underline-offset:5px}
.article-header{padding:116px 0 38px;border-bottom:1px solid var(--line);background:var(--cream)}.breadcrumbs{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:34px;color:var(--muted);font-size:13px}.breadcrumbs a{text-decoration:none}.breadcrumbs a:hover{text-decoration:underline}.article-header h1{max-width:940px;font-size:clamp(30px,3.5vw,48px);line-height:1.3;letter-spacing:-.04em}.article-meta{display:flex;gap:14px;margin-top:24px;color:var(--muted);font-size:13px}.article-meta .category{color:var(--red);font-weight:800}.article-layout{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:72px;align-items:start;padding-block:44px 76px}.article-body{min-width:0;width:100%}.video-heading{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:16px;margin-bottom:16px}.video-heading h2{margin:0;font-size:20px}.video-heading span{color:var(--muted);font-size:12px}.video-placeholder{width:100%;min-width:0;display:flex;align-items:center;justify-content:center;min-height:220px;aspect-ratio:16/9;padding:30px;color:#faf8f2;text-align:center;border:1px solid #363830;border-radius:16px;background:radial-gradient(ellipse at 80% 5%,#343c27,transparent 65%),#171914}.video-symbol{display:grid;place-items:center;width:60px;height:60px;margin:0 auto 20px;border:1px solid #667050;border-radius:50%;color:var(--lime);font-size:25px}.video-placeholder strong{display:block;font-size:20px}.video-placeholder p{margin:12px 0 0;color:#b3b8a9;font-size:14px;line-height:1.8}.video-player{display:block;width:100%;aspect-ratio:16/9;border-radius:16px;background:var(--ink)}.video-error{margin:12px 0;color:var(--red);line-height:1.7}.guide-section{padding-top:42px;scroll-margin-top:100px}.guide-section h2{display:flex;align-items:baseline;gap:14px;margin:0 0 18px;font-size:24px;line-height:1.5;letter-spacing:-.025em}.guide-section h2 span{font-size:13px;font-weight:500;color:var(--red);font-variant-numeric:tabular-nums}.guide-section p{margin:0 0 16px;color:#55574d;font-size:16px;line-height:1.95}.article-note{margin-top:32px;padding:22px 24px;border-left:3px solid #9ac538;background:#edf2e2;font-size:14px;line-height:1.85}.article-note strong{display:block;margin-bottom:6px}.article-note p{margin:0;color:#4e5940}.article-sidebar{position:sticky;top:108px}.article-sidebar h2{margin:0 0 16px;font-size:12px;font-weight:800;letter-spacing:.08em}.toc{display:flex;flex-direction:column;border-left:1px solid var(--line)}.toc a{padding:10px 0 10px 18px;font-size:13px;line-height:1.7;text-decoration:none;color:var(--muted)}.toc a:hover{color:var(--ink);border-left:2px solid var(--red);margin-left:-1px}.sidebar-support{margin-top:34px;padding-top:24px;border-top:1px solid var(--line)}.sidebar-support p{font-size:13px;color:var(--muted);line-height:1.8}.sidebar-support a{font-size:13px;text-underline-offset:4px;overflow-wrap:anywhere}.related{padding-top:38px;margin-top:38px;border-top:1px solid var(--line)}.related h2{font-size:20px}.related a{display:flex;justify-content:space-between;gap:18px;padding:16px 0;border-bottom:1px solid var(--line);font-size:15px;line-height:1.6;text-decoration:none}.related a:hover{color:var(--red)}.back-link{display:inline-flex;margin-top:28px;gap:10px;text-underline-offset:5px;font-size:14px;font-weight:700}.not-found{padding:160px 0 100px;min-height:70vh}.not-found p{line-height:1.8;color:var(--muted)}.no-js{margin:100px auto 30px;max-width:800px;padding:24px;line-height:1.8}footer{display:flex;justify-content:space-between;align-items:center;gap:24px;padding:38px max(40px,calc((100vw - 1200px)/2));color:#a4a69d;background:var(--ink);font-size:13px}footer strong{display:block;margin-bottom:8px;color:white;font-size:20px}.footer-links{display:flex;gap:24px;flex-wrap:wrap}footer a{color:white;text-decoration:none}
@media(min-width:1500px){.hero-grid{gap:110px}}@media(max-width:900px){.hero-grid{grid-template-columns:1fr;gap:30px}.hero-search{max-width:600px}.article-layout{gap:36px;grid-template-columns:minmax(0,1fr) 200px}.question-meta{margin-left:0;gap:12px}.question-meta .reading{display:none}.support-strip{align-items:start;flex-direction:column}.article-header h1{max-width:760px}}
@media(max-width:680px){.wrap{width:calc(100% - 36px)}.nav-shell{top:8px;height:54px;padding-left:8px}.brand{gap:6px}.brand img{width:30px;height:30px}.brand small,.nav-home,.nav-cta{display:none}nav a,.lang{font-size:12px;padding:9px 8px}.help-hero{padding:104px 0 34px}.eyebrow{font-size:11px;margin-bottom:20px}.lead{font-size:15px}.help-main{padding-top:25px}.topic-bar{align-items:start;flex-direction:column;gap:14px;padding-bottom:20px}.filter{font-size:12px;padding:10px 13px}.question-link{grid-template-columns:25px 1fr 30px;gap:12px;padding:24px 0}.question-link:hover{padding-inline:4px}.question-no{font-size:12px}.question-summary{font-size:13px}.arrow{width:30px;height:30px;font-size:18px}.question-title{font-size:18px}.question-label{font-size:10px}.support-strip{margin-top:34px;padding:25px 22px}.support-strip h2{font-size:20px}.article-header{padding:94px 0 30px}.breadcrumbs{margin-bottom:26px;font-size:12px}.article-layout{display:flex;flex-direction:column;gap:0;padding-top:28px}.article-sidebar{position:static;order:-1;width:100%;margin-bottom:30px}.toc{display:flex;flex-flow:row wrap;gap:8px;border:0}.toc a{padding:8px 11px;border:1px solid var(--line);border-radius:8px;font-size:12px}.toc a:hover{border:1px solid var(--ink);margin:0}.sidebar-support{display:none}.guide-section{padding-top:30px}.guide-section h2{font-size:21px}.guide-section p{font-size:15px}.video-placeholder{aspect-ratio:auto;min-height:195px;padding:24px 18px}.video-placeholder strong{font-size:18px}.video-symbol{width:44px;height:44px;font-size:20px;margin-bottom:14px}.video-placeholder p{font-size:12px}.video-heading span{font-size:11px}.article-meta{flex-wrap:wrap;font-size:12px}footer{align-items:start;flex-direction:column;padding:32px 18px}.footer-links{gap:18px}}
.help-hero h1{font-size:clamp(32px,3.4vw,49px);line-height:1.3;letter-spacing:-.04em}.hero-grid{grid-template-columns:1.5fr 1fr;gap:36px}.collection-heading{display:flex;justify-content:space-between;align-items:center;gap:28px;margin-bottom:26px}.collection-heading .eyebrow{margin-bottom:10px;font-size:10px}.collection-heading h2{margin:0;font-size:28px;letter-spacing:-.03em}.collection-heading p:not(.eyebrow){max-width:720px;margin:12px 0 0;font-size:14px;color:var(--muted);line-height:1.8}.collection-link{flex-shrink:0;font-size:13px;font-weight:700;text-underline-offset:5px}.service-scope{margin:0 0 8px;padding:16px 20px;border-left:3px solid var(--red);background:var(--cream);font-size:14px;line-height:1.8;color:var(--muted)}.article-body>.guide-section:first-child{padding-top:0}.article-actions{display:flex;flex-wrap:wrap;align-items:center;gap:18px;margin-top:32px}.article-actions a{font-size:14px;text-underline-offset:5px;line-height:1.6}.article-actions a:first-child{padding:14px 18px;background:var(--ink);color:var(--lime);border-radius:8px;text-decoration:none}.article-actions a:hover{color:var(--red)}.guide-section p{white-space:pre-line}
@media(max-width:900px){.hero-grid{grid-template-columns:1fr;gap:30px}.collection-heading{align-items:start;flex-direction:column;gap:16px}}
@media(max-width:680px){.help-hero h1{font-size:32px}.collection-heading h2{font-size:25px}.article-actions{align-items:start;flex-direction:column}}

@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.question-link{transition:none}}
.guide-section ul,.guide-section ol{margin:0 0 20px;padding-left:24px;color:#55574d;font-size:16px;line-height:1.9}.guide-section li{padding-left:4px;margin-bottom:6px}.guide-section li::marker{color:var(--red)}.guide-section h3{margin:24px 0 12px;font-size:18px;line-height:1.6}.contact-panel{margin-top:32px;padding:24px;background:var(--lime);border-radius:12px}.contact-panel h2{margin:0 0 12px;font-size:22px}.contact-panel p{font-size:15px;line-height:1.8;color:#485434}.contact-panel a{display:inline-block;max-width:100%;font-weight:700;overflow-wrap:anywhere;text-underline-offset:5px}

@media(max-width:380px){.brand{font-size:13px;gap:4px}.brand img{width:26px;height:26px}nav{gap:1px}nav a,.lang{font-size:11px;padding:9px 6px;white-space:nowrap}}

/* Compact directory header: keep the article list close to the navigation. */
.help-hero{padding:108px 0 24px;background:var(--paper)}
.help-hero .hero-grid{display:grid;grid-template-columns:1fr minmax(280px,460px);align-items:center;gap:24px}
.help-hero h1{font-size:30px;line-height:1.3;letter-spacing:-.03em}
.help-title .collection-link{display:inline-block;margin-top:10px;font-size:12px;color:var(--muted)}
.help-hero .search-box{padding:12px 16px;border-color:var(--line);border-radius:10px}
.help-main{padding-top:24px}
.collection-heading{margin-bottom:20px;gap:0}
.collection-heading h2{font-size:20px}
.collection-heading p:not(.eyebrow){margin:0;font-size:13px}
@media(max-width:680px){.help-hero{padding:88px 0 20px}.help-hero .hero-grid{grid-template-columns:1fr;gap:18px}.help-hero h1{font-size:26px}.help-main{padding-top:20px}.help-hero .search-box input{font-size:14px}.topic-bar{padding-bottom:18px}}
/* Help is organized by learning format, common questions and fault symptoms. */
.guide-jumps{display:flex;flex-wrap:wrap;gap:8px;padding-bottom:20px;border-bottom:1px solid var(--line)}.guide-jumps a{padding:10px 16px;border:1px solid var(--line);border-radius:8px;font-size:14px;background:transparent;color:var(--ink)}.guide-jumps a:hover{background:var(--cream)}
.help-section{padding-top:30px;scroll-margin-top:90px}.help-section+.help-section{margin-top:18px}.help-section-heading{margin-bottom:18px}.help-section-heading h2{display:flex;align-items:baseline;gap:12px;margin:0;font-size:25px;line-height:1.4;letter-spacing:-.03em}.help-section-heading h2>span{font-size:12px;color:var(--red);font-weight:600;letter-spacing:0}.help-section-heading p{margin:8px 0 0;font-size:13px;line-height:1.7;color:var(--muted)}
.video-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.video-card{min-width:0;overflow:hidden;border:1px solid var(--line);border-radius:10px;background:var(--cream)}
.top-faq-list{display:grid;grid-template-columns:1fr 1fr;align-items:start;column-gap:32px}.faq-answer{border-bottom:1px solid var(--line)}.faq-answer summary{display:flex;align-items:baseline;gap:12px;cursor:pointer;padding:18px 0;list-style:none}.faq-answer summary::-webkit-details-marker{display:none}.faq-answer summary:focus-visible{outline:3px solid var(--red);outline-offset:3px}.faq-number{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}.faq-answer h3{margin:0;font-size:15px;line-height:1.65;font-weight:700;flex:1}.faq-toggle{width:18px;height:18px;flex-shrink:0;align-self:center;color:var(--red)}.faq-answer[open] .faq-toggle{transform:rotate(180deg)}.faq-answer-body{padding:0 26px 20px}.faq-answer-body p{margin:0 0 12px;font-size:14px;line-height:1.85;color:#55574d}.faq-answer-body a{font-size:13px;font-weight:600;text-underline-offset:4px}
.trouble-list{display:grid;grid-template-columns:1fr 1fr;gap:0 32px}.trouble-link{display:flex;gap:16px;align-items:center;padding:20px 0;border-bottom:1px solid var(--line);text-decoration:none}.trouble-link>div{flex:1}.trouble-number{font-size:12px;color:var(--red)}.trouble-link h3{margin:0 0 6px;font-size:17px}.trouble-link p{margin:0;color:var(--muted);font-size:13px;line-height:1.7}.trouble-link:hover h3{color:var(--red)}
@media(max-width:900px){.video-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.top-faq-list{grid-template-columns:1fr}}
@media(max-width:680px){.video-cards{grid-template-columns:1fr}.guide-jumps{gap:6px}.guide-jumps a{padding:9px 11px;font-size:12px}.help-section{padding-top:24px}.help-section-heading h2{font-size:22px}.trouble-list{grid-template-columns:1fr}.faq-answer h3{font-size:14px}.faq-answer-body{padding-left:24px;padding-right:0}}


.video-cover{position:relative;display:block;width:100%;aspect-ratio:16/9;overflow:hidden;background:var(--cream);color:var(--ink);text-decoration:none}.video-cover img{display:block;width:100%;height:100%;object-fit:cover}.video-cover:focus-visible{outline:3px solid var(--red);outline-offset:-3px}.video-cover-fallback:not([hidden]){display:flex;align-items:center;justify-content:center;width:100%;height:100%;padding:18px;text-align:center;font-size:14px;font-weight:700;line-height:1.5}

.video-play{position:absolute;inset:50% auto auto 50%;transform:translate(-50%,-50%);display:flex;align-items:center;justify-content:center;width:42px;height:42px;border-radius:50%;background:rgba(23,25,19,.23);color:#fff;pointer-events:none}.video-play svg{width:25px;height:25px;fill:currentColor}