:root{--ink:#1b1e24;--muted:#676c76;--blue:#4169e1;--soft:#eef2ff;--paper:#f7f8fa;--line:#dfe2e8}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);font-family:Arial,"Microsoft YaHei","PingFang SC",sans-serif;line-height:1.85}img{display:block;max-width:100%;height:auto}.shell{width:min(1180px,calc(100% - 40px));margin:auto}a{color:inherit}.header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line)}.header-grid{min-height:68px;display:grid;grid-template-columns:190px 1fr auto;align-items:center;gap:24px}.brand img{height:32px;max-width:160px;width:auto}.crumb{text-align:center;color:#6a6f78;font-size:13px}.header-cta{display:inline-flex;min-height:44px;align-items:center;padding:0 18px;border:1px solid #22262e;border-radius:999px;text-decoration:none;font-weight:900}
.hero{padding:92px 0 72px;text-align:center}.hero-inner{max-width:900px}.eyebrow,.section-title>span,.article aside>span{font-size:10px;letter-spacing:.17em;font-weight:900;color:#4566c9}.hero h1{margin:10px 0 20px;font-size:clamp(46px,7vw,86px);line-height:.98;letter-spacing:-.055em}.lead{max-width:780px;margin:auto;color:#626772;font-size:18px}.hero-actions{display:flex;justify-content:center;gap:18px;align-items:center;flex-wrap:wrap;margin-top:30px}.primary{display:inline-flex;min-height:52px;align-items:center;padding:0 22px;background:#1f232b;color:#fff;text-decoration:none;border-radius:999px;font-weight:900}.text-link{text-decoration:none;color:#405aa9;font-weight:800}
.photo-band{padding:0 0 90px}.photo-grid{display:grid;grid-template-columns:1.35fr .825fr .825fr;gap:16px}.photo-grid figure{margin:0;background:var(--paper);border:1px solid var(--line);padding:14px}.photo-grid img{width:100%;height:360px;object-fit:contain;background:#fff}.photo-large img{height:430px}.photo-grid figcaption{padding-top:10px;color:#686d77;font-size:13px}.photo-grid figcaption b{color:#385fc8;margin-right:8px}
.article{padding:82px 0;background:var(--paper)}.article-grid{display:grid;grid-template-columns:250px 1fr;gap:64px}.article aside{position:sticky;top:96px;align-self:start}.article aside nav{display:flex;flex-direction:column;margin-top:16px;border-top:1px solid var(--line)}.article aside a{padding:12px 0;border-bottom:1px solid var(--line);text-decoration:none;color:#535966}.article-copy{max-width:760px}.article h2,.section-title h2,.device-grid h2,.final h2{margin:0;font-size:clamp(31px,3.8vw,48px);line-height:1.12;letter-spacing:-.035em}.article-copy p{font-size:17px;color:#626772}
.steps{padding:96px 0}.section-title{display:grid;grid-template-columns:180px 1fr;gap:32px;margin-bottom:38px}.step-grid{border-top:1px solid #cfd3db}.step-grid article{display:grid;grid-template-columns:80px .78fr 1.22fr;gap:32px;align-items:center;padding:34px 0;border-bottom:1px solid var(--line)}.step-no{font-size:42px;font-weight:300;color:#a7acb7}.step-copy h3{font-size:25px;line-height:1.2;margin:0 0 10px}.step-copy p{color:var(--muted)}.step-copy a{display:inline-flex;margin-top:8px;padding:9px 17px;border:1px solid #22262e;border-radius:999px;text-decoration:none;font-weight:900}.step-grid figure{margin:0;background:var(--paper);padding:14px}.step-grid img{width:100%;max-height:380px;object-fit:contain;background:#fff}
.device-note{padding:72px 0;background:var(--soft)}.device-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.device-grid>div{padding:34px;background:#fff;border-top:3px solid #20242c}.device-grid>div>span{font-size:10px;letter-spacing:.16em;font-weight:900;color:#4566c9}.device-grid p{color:var(--muted)}.device-grid a{display:inline-flex;margin-top:8px;padding:10px 18px;border-radius:999px;background:#20242c;color:#fff;text-decoration:none;font-weight:900}
.related{padding:72px 0}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.related-grid a{display:grid;grid-template-columns:72px 1fr auto;align-items:center;gap:14px;padding:22px;border:1px solid var(--line);text-decoration:none}.related-grid small{color:#4566c9;font-weight:900}
.faq{padding:88px 0;background:#f7f8fa}.faq-head{margin-bottom:26px}.faq-list{max-width:900px;margin-left:auto}.faq-list details{border-top:1px solid var(--line)}.faq-list details:last-child{border-bottom:1px solid var(--line)}.faq-list summary{list-style:none;cursor:pointer;padding:20px 2px;font-size:18px;font-weight:900}.faq-list summary::-webkit-details-marker{display:none}.faq-list summary:after{content:"+";float:right;color:#4566c9}.faq-list details[open] summary:after{content:"−"}.faq-list p{margin:-2px 0 22px;color:var(--muted)}
.final{padding:82px 0;text-align:center;background:#17191e;color:#fff}.final-inner{max-width:780px}.final p{font-size:10px;letter-spacing:.17em;color:#aeb8dc;font-weight:900}.final span{display:block;color:#c7cad2;margin-top:10px}.final a{display:inline-flex;margin-top:26px;min-height:52px;align-items:center;padding:0 22px;background:#fff;color:#17191e;text-decoration:none;border-radius:999px;font-weight:900}.footer{padding:48px 0 86px;background:#0d0f13;color:#e0e2e8}.footer-grid{display:grid;grid-template-columns:1fr auto;gap:34px}.footer img{height:31px;max-width:155px;width:auto}.footer p{color:#999da7;font-size:13px}.footer nav{display:flex;gap:18px;flex-wrap:wrap}.footer nav a{text-decoration:none;color:#e0e2e8;font-size:14px}.mobile-bar{display:none}
@media(max-width:900px){.header-grid{grid-template-columns:1fr auto}.crumb{display:none}.photo-grid{grid-template-columns:1fr 1fr}.photo-large{grid-column:1/-1}.article-grid,.section-title{grid-template-columns:1fr}.article aside{position:static}.article aside nav{display:grid;grid-template-columns:1fr 1fr}.step-grid article{grid-template-columns:60px 1fr}.step-grid figure{grid-column:2}.device-grid,.related-grid{grid-template-columns:1fr 1fr}}
@media(max-width:600px){body{font-size:15px;padding-bottom:62px}.shell{width:min(100% - 28px,1180px)}.header-grid{min-height:62px}.brand img{height:28px}.header-cta{font-size:12px;padding:0 12px}.hero{padding:58px 0 46px}.hero h1{font-size:clamp(42px,14vw,60px)}.lead{font-size:16px}.hero-actions{flex-direction:column}.primary{width:100%;justify-content:center}.photo-band{padding-bottom:58px}.photo-grid,.device-grid,.related-grid{grid-template-columns:1fr}.photo-grid img,.photo-large img{height:auto;max-height:300px}.article,.steps,.faq{padding:62px 0}.article aside nav{grid-template-columns:1fr}.step-grid article{grid-template-columns:48px 1fr;gap:14px;padding:28px 0}.step-no{font-size:30px}.step-grid figure{grid-column:1/-1}.step-grid img{max-height:300px}.mobile-bar{position:fixed;left:0;right:0;bottom:0;z-index:80;display:flex;min-height:60px;align-items:center;justify-content:space-between;padding:8px 14px;background:rgba(23,25,30,.97);color:#fff}.mobile-bar a{display:inline-flex;min-width:110px;min-height:40px;align-items:center;justify-content:center;background:#fff;color:#17191e;text-decoration:none;border-radius:999px;font-weight:900}}