:root{--ink:#172427;--tone:#3f8f74;--accent:#dd2731;--soft:#f4f5f0;--line:#d8dfda;--muted:#66716c;--shell:1420px}.shell{width:min(calc(100% - 56px),var(--shell));margin:auto}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:78px}
body{margin:0;min-width:320px;font-family:Arial,"Microsoft YaHei","PingFang SC",sans-serif;color:var(--ink);line-height:1.76;background:#fff}
img{display:block;max-width:100%}a{text-decoration:none;color:inherit}
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line)}
.header-shell{height:74px;display:grid;grid-template-columns:270px 1fr 145px;gap:24px;align-items:center}
.brand{display:flex;align-items:center;gap:10px;font-size:9px;font-weight:900;letter-spacing:.13em}
.brand img,.footer-logo{height:28px;width:auto;background:var(--ink);padding:5px 9px}
.site-nav{display:flex;justify-content:center;gap:24px;color:var(--muted);font-size:12px;font-weight:800}
.top-btn,.primary{background:var(--accent);color:#fff;font-weight:900}
.top-btn{padding:10px 14px;text-align:center;font-size:12px}.primary{display:inline-flex;padding:15px 20px}
.menu-button{display:none}.kicker{margin:0 0 12px;color:var(--tone);font-size:10px;font-weight:900;letter-spacing:.15em}
h1{margin:0;font-size:clamp(54px,6.8vw,98px);line-height:.94;letter-spacing:-.068em}
h2{margin:0;font-size:clamp(34px,4vw,52px);line-height:1.15;letter-spacing:-.045em}
p{color:var(--muted)}figure{margin:0}figcaption{margin-top:8px;color:var(--muted);font-size:10px}
.faq-list{margin-top:30px;border-top:2px solid var(--ink)}
details{border-bottom:1px solid var(--line)}summary{list-style:none;position:relative;padding:20px 45px 20px 0;font-weight:850;cursor:pointer}
summary span{position:absolute;right:0}.faq-list p{margin:-3px 0 20px}
.mobile-download-bar{display:none}
@media(max-width:850px){
.header-shell{grid-template-columns:1fr auto}.site-nav,.top-btn{display:none}.menu-button{display:block}
.site-nav.is-open{display:grid;position:absolute;top:70px;left:18px;right:18px;background:#fff;border:1px solid var(--line);padding:12px}
}
@media(max-width:600px){
body{padding-bottom:60px}.brand span{display:none}h1{font-size:clamp(44px,13vw,61px)}
.mobile-download-bar{position:fixed;left:0;right:0;bottom:0;z-index:90;height:60px;background:var(--ink);color:#fff;display:flex;align-items:center;justify-content:space-between;padding:8px 14px}
.mobile-download-bar a{background:var(--accent);padding:9px 15px;font-weight:900}
}
.hero{background:var(--soft)}.hero-route{display:grid;grid-template-columns:1fr 90px 1fr;border:1px solid var(--line);border-top:0}.hero-route span,.hero-route b{display:grid;place-items:center;height:52px;border-right:1px solid var(--line);font-size:9px;font-weight:900}.hero-route b{color:var(--accent)}.hero-shell{display:grid;grid-template-columns:.82fr 1.18fr;gap:70px;align-items:center;padding:75px 0}.hero-copy>p{font-size:18px}.hero img{width:100%;max-height:500px;object-fit:contain;background:#fff}
.route,.visuals,.migration,.faq{padding:95px 0}.copy{max-width:900px}.route-board{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:35px}.route-board article{display:grid;grid-template-columns:1fr 55px 1fr;gap:10px;padding:22px;background:var(--soft);border-top:3px solid var(--tone)}.route-board small{display:block;color:#85938d;font-size:8px;font-weight:900}.route-board article>b{display:grid;place-items:center;color:var(--accent)}.route-board p,.route-board a{grid-column:1/-1}.route-board a{color:var(--tone);font-size:11px;font-weight:900}.dark-btn{display:inline-flex;margin-top:25px;background:var(--ink);color:#fff;padding:14px 18px;font-weight:900}
.choose{display:grid;grid-template-columns:150px 1fr;gap:50px;padding:95px 0}.choose-no{font-size:92px;font-weight:950;line-height:.8;color:#dce5df}.choose-list{margin-top:34px;border-top:2px solid var(--ink)}.choose-list a{display:grid;grid-template-columns:70px 1fr 230px;gap:20px;align-items:center;padding:17px 0;border-bottom:1px solid var(--line)}.choose-list b{color:var(--tone)}.choose-list em{font-style:normal;color:var(--accent);font-size:11px;font-weight:900}
.gallery{display:grid;grid-template-columns:1.25fr .75fr;grid-template-rows:1fr 1fr;gap:20px;margin-top:38px}.gallery figure{margin:0}.gallery .big{grid-row:1/3}.gallery img{width:100%;height:100%;object-fit:contain;background:var(--soft)}
.download{background:var(--ink);color:#fff}.download-shell{display:grid;grid-template-columns:.92fr 1.08fr;gap:65px;align-items:center;padding:95px 0}.download p{color:#afbbb6}.steps{margin-top:30px;border-top:1px solid #405255}.steps article{display:grid;grid-template-columns:60px 180px 1fr;gap:18px;padding:14px 0;border-bottom:1px solid #405255}.steps span{color:#79b79e}.steps h3{margin:-2px 0 0;font-size:15px}.steps p{margin:0;font-size:10px}.download img{width:100%;max-height:480px;object-fit:contain;background:#0d1517}
.migration{display:grid;grid-template-columns:.85fr 1.15fr;gap:65px;align-items:center}.migration img{width:100%;max-height:470px;object-fit:contain;background:var(--soft)}.outline{display:inline-flex;margin-top:22px;border:1px solid var(--ink);padding:13px 17px;font-weight:900}
.device-footer{border:1px solid var(--line);margin-bottom:24px}.footer-route{display:grid;grid-template-columns:1fr 80px 1fr 80px 1fr;border-bottom:1px solid var(--line)}.footer-route span,.footer-route b{display:grid;place-items:center;min-height:58px;border-right:1px solid var(--line);font-size:9px;font-weight:900}.footer-route b{color:var(--accent)}.footer-route span:nth-child(5){background:var(--ink);color:#fff}.footer-body{display:grid;grid-template-columns:180px 1fr 220px;gap:35px;align-items:center;padding:32px}.footer-body p{font-size:10px}.footer-body>a{background:var(--accent);color:#fff;padding:14px 17px;text-align:center;font-weight:900}.footer-bottom{display:flex;justify-content:space-between;padding:14px 20px;border-top:1px solid var(--line);color:#86918c;font-size:9px;font-weight:900}
@media(max-width:850px){.hero-shell,.download-shell,.migration{grid-template-columns:1fr}.route-board{grid-template-columns:1fr}.footer-body{grid-template-columns:1fr}}
@media(max-width:600px){.shell{width:min(calc(100% - 28px),var(--shell))}.hero-route{grid-template-columns:1fr 45px 1fr}.hero-shell{padding:52px 0}.hero-copy>p{font-size:16px}.route,.visuals,.migration,.faq{padding:70px 0}.choose{grid-template-columns:1fr;padding:70px 0}.choose-no{font-size:55px}.choose-list a{grid-template-columns:1fr;gap:4px}.gallery{grid-template-columns:1fr;grid-template-rows:auto}.gallery .big{grid-row:auto}.download-shell{padding:70px 0}.steps article{grid-template-columns:1fr;gap:4px}.footer-route{grid-template-columns:1fr}.footer-route b{display:none}.footer-body{padding:25px 15px}.footer-bottom{display:grid;gap:5px}}