:root{
  --ink:#202427;
  --ink2:#343a3f;
  --red:#df1f2b;
  --red2:#ad111b;
  --sage:#839487;
  --sand:#f3eee4;
  --sand2:#e9e0d2;
  --paper:#fff;
  --mist:#f4f5f4;
  --line:#daddda;
  --muted:#6d7370;
  --white:#fff;
  --shell:1380px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:82px}
body{
  margin:0;min-width:320px;color:var(--ink);background:var(--paper);
  font-family:Arial,"Microsoft YaHei","PingFang SC","Segoe UI",sans-serif;
  line-height:1.75;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility
}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button,a{-webkit-tap-highlight-color:transparent}
button{font:inherit}
.skip-link{position:fixed;top:-90px;left:18px;z-index:1000;padding:10px 15px;color:#fff;background:var(--red);font-weight:900}
.skip-link:focus{top:18px}
.header-shell,.hero-shell,.hero-banner,.section,.final-shell,.footer-shell{width:min(calc(100% - 56px),var(--shell));margin-inline:auto}

.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.97);border-bottom:1px solid var(--line);backdrop-filter:blur(14px)}
.header-shell{min-height:76px;display:grid;grid-template-columns:270px 1fr 120px;gap:30px;align-items:center}
.brand{width:max-content;display:flex;align-items:center;gap:12px}
.brand-logo{padding:6px 12px;background:var(--ink);border-left:4px solid var(--red)}
.brand-logo img{width:auto;height:29px;object-fit:contain}
.brand-tag{color:#858b88;font-size:8px;font-weight:900;letter-spacing:.13em}
.site-nav{display:flex;justify-content:center;gap:29px;color:#686e6b;font-size:12px;font-weight:800}
.site-nav a{padding:24px 0 22px}
.site-nav a:hover,.site-nav a:focus-visible{color:var(--red)}
.header-cta{justify-self:end;padding:10px 14px;color:#fff;background:var(--ink);font-size:12px;font-weight:900}
.header-cta:hover,.header-cta:focus-visible{background:var(--red)}
.menu-button{display:none;width:44px;height:44px;background:#fff;border:1px solid var(--line)}
.menu-button span{display:block;width:19px;height:2px;margin:4px auto;background:var(--ink)}

.hero{overflow:hidden;padding-top:0;border-bottom:1px solid var(--line);background:linear-gradient(90deg,#fff 0 73%,var(--sand) 73% 100%)}
.hero-shell{min-height:480px;display:grid;grid-template-columns:1fr 350px;gap:80px;align-items:center;padding:76px 0 55px}
.eyebrow,.section-label{margin:0 0 14px;color:var(--red);font-size:10px;font-weight:900;letter-spacing:.16em;text-transform:uppercase}
.hero h1{margin:0;max-width:900px;font-size:clamp(58px,7.3vw,104px);line-height:.95;letter-spacing:-.07em}
.hero-lead{max-width:820px;margin:28px 0 0;color:#555c58;font-size:18px;line-height:1.9}
.hero-actions{display:flex;align-items:center;flex-wrap:wrap;gap:24px;margin-top:34px}
.primary-button{min-width:275px;min-height:60px;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px 20px;color:#fff;background:var(--red);font-weight:900}
.primary-button:hover,.primary-button:focus-visible{background:var(--red2)}
.primary-button b{font-size:21px}
.secondary-link{padding-bottom:3px;border-bottom:1px solid currentColor;font-size:13px;font-weight:850}
.hero-checks{display:grid;grid-template-columns:repeat(4,1fr);max-width:780px;margin:35px 0 0;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.hero-checks div{padding:11px 13px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.hero-checks dt{color:#929895;font-size:8px;font-weight:900}
.hero-checks dd{margin:3px 0 0;font-size:10px;font-weight:900}
.hero-note{align-self:end;margin-bottom:10px;padding:28px 0;border-top:4px solid var(--ink);border-bottom:1px solid #d5ccbe}
.hero-note span{color:var(--red);font-size:9px;font-weight:900;letter-spacing:.13em}
.hero-note strong{display:block;margin-top:43px;font-size:18px;line-height:1.5}
.hero-note p{margin:11px 0 0;color:var(--muted);font-size:12px}
.hero-banner{margin-bottom:42px}
.hero-banner img{width:100%;max-height:440px;object-fit:cover}
.hero-banner figcaption{margin-top:10px;color:var(--muted);font-size:10px}

.section{padding-top:106px;padding-bottom:106px}
.section-head{display:grid;grid-template-columns:78px 1fr;gap:30px;max-width:1060px}
.section-index{color:var(--red);font-size:56px;font-weight:950;line-height:1}
.section-head h2,.source-intro h2,.device-copy h2,.install-intro h2,.privacy-layout h2,.update-layout h2,.help-head h2,.final-copy h2{margin:0;font-size:clamp(34px,4.3vw,54px);line-height:1.16;letter-spacing:-.045em}
.section-head > div > p:not(.section-label),.source-intro > p:not(.section-label),.device-copy > p:not(.section-label),.install-intro > p:not(.section-label),.privacy-layout > div > p:not(.section-label),.update-layout > div:first-child > p:not(.section-label),.help-head > p:not(.section-label){margin:20px 0 0;color:var(--muted)}

.download-section{background:#fff}
.download-strip{display:grid;grid-template-columns:1fr 1fr 1fr 210px;margin-top:48px;border-top:2px solid var(--ink);border-left:1px solid var(--line)}
.download-strip > div{min-height:120px;display:grid;align-content:center;padding:20px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.download-strip span{color:var(--red);font-size:9px;font-weight:900;letter-spacing:.1em}
.download-strip strong{margin-top:5px;font-size:14px}
.download-strip > a{min-height:120px;display:grid;place-items:center;padding:20px;color:#fff;background:var(--ink);text-align:center;font-size:12px;font-weight:900}
.download-strip > a:hover,.download-strip > a:focus-visible{background:var(--red)}
.download-disclaimer{margin:18px 0 0;padding-left:14px;color:var(--muted);border-left:3px solid var(--red);font-size:12px}

.source-section{background:var(--sand)}
.source-intro{max-width:940px}
.source-intro .section-index,.device-copy .section-index,.install-intro .section-index,.privacy-layout .section-index,.update-layout .section-index,.help-head .section-index{display:block;margin-bottom:12px}
.source-lines{margin-top:48px;border-top:2px solid var(--ink)}
.source-lines article{display:grid;grid-template-columns:65px 1fr 150px;gap:24px;align-items:center;min-height:145px;padding:22px 0;border-bottom:1px solid #d4cabd}
.source-no{width:52px;height:52px;display:grid;place-items:center;color:#fff;background:var(--ink);font-weight:950}
.source-lines article:nth-child(even) .source-no{background:var(--red)}
.source-lines article > div:nth-child(2) > span{color:var(--red);font-size:8px;font-weight:900;letter-spacing:.12em}
.source-lines h3{margin:3px 0 6px;font-size:19px}
.source-lines p{margin:0;color:var(--muted);font-size:12px}
.source-lines article > strong{color:#8b8176;font-size:10px;text-align:right}

.device-section{background:#fff}
.device-layout{display:grid;grid-template-columns:.82fr 1.18fr;gap:76px;align-items:center}
.device-tabs{display:grid;grid-template-columns:repeat(3,1fr);margin-top:32px;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.device-tab{min-height:54px;color:var(--ink);background:#fff;border:0;border-right:1px solid var(--line);border-bottom:1px solid var(--line);cursor:pointer;font-size:11px;font-weight:900}
.device-tab.is-active{color:#fff;background:var(--ink)}
.device-answer{padding:27px;border:1px solid var(--line);border-top:0;background:var(--mist)}
.device-answer > span{color:var(--red);font-size:8px;font-weight:900;letter-spacing:.12em}
.device-answer h3{margin:6px 0 9px;font-size:25px}
.device-answer > p{margin:0;color:var(--muted)}
.device-answer dl{display:grid;grid-template-columns:repeat(3,1fr);margin:22px 0 0;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.device-answer dl div{padding:10px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);background:#fff}
.device-answer dt{color:#929895;font-size:8px;font-weight:900}
.device-answer dd{margin:4px 0 0;font-size:10px;font-weight:850}
.device-visual{margin:0}
.device-visual img{width:100%;max-height:520px;object-fit:contain}
.device-visual figcaption{margin-top:11px;color:var(--muted);font-size:10px;text-align:center}

.alert-section{background:var(--mist)}
.alert-table{margin-top:50px;border-top:2px solid var(--ink)}
.alert-table article{display:grid;grid-template-columns:140px 1fr 1.3fr;gap:24px;padding:22px 0;border-bottom:1px solid var(--line)}
.alert-table span{color:var(--red);font-size:10px;font-weight:900}
.alert-table strong{font-size:13px}
.alert-table p{margin:0;color:var(--muted);font-size:12px}

.install-section{background:#fff}
.install-intro{max-width:940px}
.install-flow{display:grid;grid-template-columns:repeat(5,1fr);margin:50px 0 0;padding:0;list-style:none;border-top:2px solid var(--ink);border-left:1px solid var(--line)}
.install-flow li{min-height:245px;padding:25px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.install-flow li:nth-child(even){background:var(--mist)}
.install-flow span{color:var(--red);font-size:28px;font-weight:950}
.install-flow h3{margin:48px 0 8px;font-size:18px}
.install-flow p{margin:0;color:var(--muted);font-size:12px}
.install-cta{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:20px;margin-top:24px;padding:16px 22px;color:#fff;background:var(--ink);font-weight:900}
.install-cta:hover,.install-cta:focus-visible{background:var(--red)}
.install-cta b{font-size:20px}

.privacy-section{background:var(--sand)}
.privacy-layout{display:grid;grid-template-columns:1.08fr .92fr;gap:75px;align-items:center}
.privacy-layout figure{margin:0;padding:18px;background:#fff;border:1px solid #d4cabd}
.privacy-layout figure img{width:100%;object-fit:contain}
.privacy-note{padding:15px 0 0;border-top:1px solid #d4cabd;font-size:11px!important}

.fake-section{background:#fff}
.warning-list{display:grid;grid-template-columns:repeat(3,1fr);margin-top:48px;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.warning-list article{min-height:215px;padding:25px;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.warning-list article:nth-child(2),.warning-list article:nth-child(4),.warning-list article:nth-child(6){background:var(--mist)}
.warning-list span{color:var(--red);font-size:10px;font-weight:900}
.warning-list h3{margin:26px 0 8px;font-size:18px}
.warning-list p{margin:0;color:var(--muted);font-size:12px}

.update-section{background:var(--ink);color:#fff}
.update-layout{display:grid;grid-template-columns:.72fr 1.28fr;gap:75px;align-items:start}
.update-layout h2{color:#fff}
.update-layout > div:first-child > p:not(.section-label){color:#afb4b2}
.update-steps{border-top:1px solid #4a4f52}
.update-steps article{padding:26px 0;border-bottom:1px solid #4a4f52}
.update-steps b{color:#ff7d86;font-size:9px;letter-spacing:.12em}
.update-steps h3{margin:6px 0 8px;font-size:21px}
.update-steps p{margin:0;color:#b9bdbc;font-size:12px}

.help-section{background:var(--sand)}
.help-head{max-width:960px}
.help-visual{margin:46px 0 0}
.help-visual img{width:100%;max-height:500px;object-fit:cover}
.help-visual figcaption{margin-top:11px;color:var(--muted);font-size:10px}
.help-cases{display:grid;grid-template-columns:repeat(3,1fr);margin-top:28px;border-top:1px solid #d4cabd;border-left:1px solid #d4cabd}
.help-cases article{min-height:180px;padding:22px;border-right:1px solid #d4cabd;border-bottom:1px solid #d4cabd}
.help-cases article:nth-child(even){background:rgba(255,255,255,.45)}
.help-cases span{color:var(--red);font-size:9px;font-weight:900}
.help-cases strong{display:block;margin-top:24px;font-size:16px}
.help-cases p{margin:6px 0 0;color:var(--muted);font-size:11px}

.faq-section{background:#fff}
.faq-list{margin-top:50px;border-top:2px solid var(--ink)}
.faq-list details{border-bottom:1px solid var(--line)}
.faq-list summary{position:relative;padding:24px 55px 24px 0;font-size:16px;font-weight:850;cursor:pointer;list-style:none}
.faq-list summary::-webkit-details-marker{display:none}
.faq-list summary span{position:absolute;right:4px;top:20px;width:30px;height:30px;display:grid;place-items:center;color:var(--red);border:1px solid var(--line);border-radius:50%;transition:transform .2s ease}
.faq-list details[open] summary span{transform:rotate(45deg)}
.faq-list p{margin:-2px 0 23px;color:var(--muted)}

.related-section{background:var(--mist)}
.related-links{display:grid;grid-template-columns:repeat(3,1fr);margin-top:50px;border-top:1px solid var(--line);border-left:1px solid var(--line)}
.related-links a{min-height:140px;display:grid;align-content:center;padding:23px;background:#fff;border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
.related-links a:hover,.related-links a:focus-visible{background:var(--sand)}
.related-links strong{color:var(--red);font-size:15px}
.related-links span{margin-top:6px;color:var(--muted);font-size:11px}

.final-section{background:#fff}
.final-shell{min-height:285px;display:grid;grid-template-columns:110px 1fr 230px;gap:42px;align-items:center;padding:44px 0;border-top:5px solid var(--red);border-bottom:1px solid var(--line)}
.final-number{width:90px;height:110px;display:grid;place-items:center;align-content:center;color:#fff;background:var(--ink)}
.final-number span{font-size:40px;font-weight:950;line-height:1}
.final-number small{margin-top:5px;color:#ff8f96;font-size:8px;font-weight:900}
.final-copy p{margin:0 0 9px;color:var(--red);font-size:9px;font-weight:900;letter-spacing:.13em}
.final-copy h2{font-size:clamp(29px,3.6vw,44px)}
.final-copy span{display:block;margin-top:13px;color:var(--muted);font-size:11px}
.final-button{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:16px 20px;color:#fff;background:var(--red);font-weight:900}
.final-button:hover,.final-button:focus-visible{background:var(--red2)}
.final-button b{font-size:20px}

.site-footer{padding:52px 0 32px;color:#b8bdbc;background:var(--ink)}
.footer-shell{display:grid;grid-template-columns:1fr auto;gap:32px 55px}
.footer-brand img{width:auto;height:34px;object-fit:contain}
.footer-brand p{max-width:810px;margin:17px 0 0;color:#787e7c;font-size:11px}
.footer-nav{display:grid;grid-template-columns:repeat(2,auto);gap:8px 25px;font-size:12px;font-weight:700}
.footer-nav a:hover,.footer-nav a:focus-visible{color:#fff}
.copyright{grid-column:1/-1;margin:5px 0 0;padding-top:21px;color:#575d5b;border-top:1px solid #3d4241;font-size:11px}
.mobile-download{display:none}

@media(max-width:1080px){
  .header-shell{grid-template-columns:240px 1fr 110px}
  .site-nav{gap:17px}
  .hero-shell{grid-template-columns:1fr 300px;gap:50px}
  .install-flow{grid-template-columns:repeat(3,1fr)}
  .warning-list{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:820px){
  html{scroll-padding-top:72px}
  .header-shell{min-height:70px;grid-template-columns:1fr auto}
  .header-cta{display:none}
  .menu-button{display:block}
  .site-nav{position:absolute;left:20px;right:20px;top:calc(100% + 8px);display:none;padding:10px;background:#fff;border:1px solid var(--line);box-shadow:0 22px 55px rgba(0,0,0,.18)}
  .site-nav.is-open{display:grid}
  .site-nav a{padding:10px 12px}
  .hero{background:#fff}
  .hero-shell{grid-template-columns:1fr}
  .hero-note{max-width:680px}
  .device-layout,.privacy-layout,.update-layout{grid-template-columns:1fr}
  .alert-table article{grid-template-columns:110px 1fr}
  .alert-table p{grid-column:2}
  .help-cases{grid-template-columns:repeat(2,1fr)}
  .final-shell{grid-template-columns:100px 1fr}
  .final-button{grid-column:2;width:230px}
  .footer-shell{grid-template-columns:1fr}
  .copyright{grid-column:auto}
}
@media(max-width:600px){
  body{padding-bottom:70px}
  .header-shell,.hero-shell,.hero-banner,.section,.final-shell,.footer-shell{width:min(calc(100% - 28px),var(--shell))}
  .brand-tag{display:none}
  .brand-logo img{height:27px}
  .hero-shell{min-height:0;padding:55px 0 42px}
  .hero h1{font-size:clamp(46px,14vw,66px)}
  .hero-lead{font-size:16px}
  .hero-actions{display:grid}
  .primary-button{min-width:0;width:100%}
  .secondary-link{justify-self:start}
  .hero-checks{grid-template-columns:repeat(2,1fr)}
  .hero-banner{margin-bottom:24px}
  .hero-banner img{object-fit:contain}
  .section{padding-top:72px;padding-bottom:72px}
  .section-head{grid-template-columns:1fr;gap:10px}
  .section-index{font-size:42px}
  .section-head h2,.source-intro h2,.device-copy h2,.install-intro h2,.privacy-layout h2,.update-layout h2,.help-head h2{font-size:clamp(30px,10vw,41px)}
  .download-strip,.device-tabs,.device-answer dl,.install-flow,.warning-list,.help-cases,.related-links{grid-template-columns:1fr}
  .download-strip > a{min-height:68px}
  .source-lines article{grid-template-columns:50px 1fr;gap:14px}
  .source-lines article > strong{grid-column:2;text-align:left}
  .alert-table article{grid-template-columns:1fr;gap:6px}
  .alert-table p{grid-column:auto}
  .install-flow li{min-height:0}
  .install-flow h3{margin-top:28px}
  .help-cases article{min-height:0}
  .faq-list summary{font-size:15px}
  .final-shell{grid-template-columns:1fr;padding:34px 0}
  .final-number{width:76px;height:90px}
  .final-button{grid-column:auto;width:100%}
  .footer-nav{grid-template-columns:1fr 1fr}
  .mobile-download{position:fixed;left:0;right:0;bottom:0;z-index:120;min-height:70px;display:flex;justify-content:space-between;align-items:center;gap:12px;padding:9px 14px;color:#fff;background:rgba(32,36,39,.97);border-top:1px solid #444a48}
  .mobile-download>div{display:flex;align-items:center;gap:10px}
  .mobile-download img{width:75px;height:auto;object-fit:contain}
  .mobile-download small,.mobile-download strong{display:block;line-height:1.2}
  .mobile-download small{color:#7c8480;font-size:9px}
  .mobile-download strong{margin-top:3px;font-size:13px}
  .mobile-download>a{padding:11px 15px;color:#fff;background:var(--red);font-size:13px;font-weight:900}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition-duration:.01ms!important}
}