/* ============================================================
   VMOS投屏 / VMOS Cast — 官网样式（Linear/Vercel 式极简高级 · 浅色）
   忠实还原已审查通过的 r1 设计：自托管 Geist / Geist Mono / Instrument Serif
   正文/标题用 Geist（含 CJK 系统字体兜底），无 Google Fonts、纯离线可用
   ============================================================ */

/* ============ self-hosted fonts（与 r1 一致，全部本地托管）============ */
@font-face{
  font-family:"Geist";
  src:url("./fonts/geist-var.woff2") format("woff2");
  font-weight:100 900;
  font-style:normal;
  font-display:swap;
}
@font-face{
  font-family:"Geist Mono";
  src:url("./fonts/geist-mono.woff2") format("woff2");
  font-weight:100 900;
  font-style:normal;
  font-display:swap;
}
@font-face{
  font-family:"Instrument Serif";
  src:url("./fonts/instrument-serif-italic.woff2") format("woff2");
  font-weight:400;
  font-style:italic;
  font-display:swap;
}

/* ============ tokens ============ */
:root{
  --bg:#ffffff;
  --bg-soft:#f7f8fa;
  --ink:#17181c;
  --ink-1:#2b2d33;
  --ink-2:#565962;
  --ink-3:#8a8d96;
  --line:rgba(17,18,22,.08);
  --line-2:rgba(17,18,22,.055);
  --line-strong:rgba(17,18,22,.13);
  --accent:#2f6bed;
  --accent-ink:#1f52cf;
  --accent-soft:#eef3ff;
  --live:#1fab5a;
  --shadow-btn:0 1px 2px rgba(17,18,22,.14),0 4px 12px rgba(17,18,22,.10);
  --shadow-card:0 1px 2px rgba(17,18,22,.04),0 6px 20px rgba(17,18,22,.05);
  --shadow-card-h:0 2px 4px rgba(17,18,22,.05),0 14px 36px rgba(17,18,22,.10);
  --shadow-hero:0 2px 6px rgba(17,18,22,.05),0 20px 50px rgba(17,18,22,.10),0 48px 100px rgba(24,44,96,.12);
  --r:14px;--r-sm:10px;--r-xs:8px;--r-pill:999px;
  --maxw:1200px;
  --sans:"Geist","PingFang SC","Microsoft YaHei","Hiragino Sans GB",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  --serif:"Instrument Serif","Songti SC",Georgia,"Times New Roman",serif;
  --mono:"Geist Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:88px;-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--bg);color:var(--ink-2);
  font-family:var(--sans);font-size:16px;line-height:1.6;font-weight:400;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;letter-spacing:-.003em;
}
h1,h2,h3,h4{color:var(--ink);font-weight:600;line-height:1.1;letter-spacing:-.02em;margin:0}
p{margin:0}
a{color:inherit;text-decoration:none}
img{max-width:100%}
::selection{background:rgba(47,107,237,.16)}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}
.section{padding:clamp(80px,11vw,160px) 0}
.section--soft{background:var(--bg-soft);border-top:1px solid var(--line-2);border-bottom:1px solid var(--line-2)}

/* ============ nav ============ */
.nav{
  position:sticky;top:0;z-index:60;
  background:rgba(255,255,255,.72);backdrop-filter:saturate(180%) blur(16px);-webkit-backdrop-filter:saturate(180%) blur(16px);
  border-bottom:1px solid transparent;transition:border-color .3s,box-shadow .3s;
}
.nav.scrolled{border-bottom-color:var(--line);box-shadow:0 1px 0 rgba(17,18,22,.02),0 8px 24px rgba(17,18,22,.04)}
.nav-in{max-width:var(--maxw);margin:0 auto;padding:0 28px;height:64px;display:flex;align-items:center;gap:28px}
.brand{display:flex;align-items:center;gap:11px}
.mark{
  width:32px;height:32px;border-radius:9px;flex:none;display:block;
  box-shadow:0 2px 6px rgba(31,82,207,.28);
}
.brand-txt{display:flex;flex-direction:column;line-height:1}
.brand-txt b{font-size:16px;font-weight:600;color:var(--ink);letter-spacing:-.01em}
.brand-txt span{font-family:var(--mono);font-size:9.5px;color:var(--ink-3);letter-spacing:.14em;margin-top:3px}
.nav-links{display:flex;align-items:center;gap:4px;margin-left:8px}
.nav-links a{padding:8px 13px;border-radius:8px;font-size:14.5px;color:var(--ink-2);font-weight:500;transition:background .2s,color .2s}
.nav-links a:hover{background:rgba(17,18,22,.05);color:var(--ink)}
.nav-right{margin-left:auto;display:flex;align-items:center;gap:10px}
.lang-switch{
  display:inline-flex;align-items:center;justify-content:center;height:38px;min-width:44px;padding:0 12px;
  border-radius:9px;font-family:var(--mono);font-size:12.5px;font-weight:500;letter-spacing:.02em;color:var(--ink-1);
  transition:background .2s,color .2s;
}
.lang-switch:hover{background:rgba(17,18,22,.05);color:var(--ink)}
.ghost-ico{width:38px;height:38px;border-radius:9px;display:grid;place-items:center;color:var(--ink-1);transition:background .2s,color .2s}
.ghost-ico:hover{background:rgba(17,18,22,.05);color:var(--ink)}
.ghost-ico svg{width:19px;height:19px}

/* ============ buttons ============ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  height:44px;padding:0 20px;border-radius:var(--r-xs);border:1px solid transparent;
  font-family:var(--sans);font-size:14.5px;font-weight:500;letter-spacing:-.01em;cursor:pointer;
  transition:transform .18s cubic-bezier(.2,.7,.3,1),box-shadow .22s,background .2s,border-color .2s,color .2s;
  white-space:nowrap;
}
.btn svg{width:16px;height:16px}
.btn-primary{background:var(--ink);color:#fff;box-shadow:var(--shadow-btn)}
.btn-primary:hover{background:#000;transform:translateY(-1px);box-shadow:0 2px 4px rgba(17,18,22,.16),0 10px 26px rgba(17,18,22,.22)}
.btn-ghost{background:#fff;color:var(--ink);border-color:var(--line-strong)}
.btn-ghost:hover{border-color:rgba(17,18,22,.28);background:#fcfcfd;transform:translateY(-1px)}
.btn-sm{height:38px;padding:0 15px;font-size:14px;border-radius:8px}
.btn-lg{height:50px;padding:0 26px;font-size:15.5px;border-radius:10px}
.btn .arw{transition:transform .22s}
.btn:hover .arw{transform:translateX(3px)}

/* ============ eyebrow / labels ============ */
.overline{
  display:inline-flex;align-items:center;gap:9px;
  font-size:12px;font-weight:500;letter-spacing:.16em;text-transform:uppercase;color:var(--accent);
  font-family:var(--sans);
}
.overline::before{content:"";width:18px;height:1px;background:currentColor;opacity:.55;display:inline-block}
.pill{
  display:inline-flex;align-items:center;gap:9px;padding:6px 15px 6px 13px;border-radius:var(--r-pill);
  background:#fff;border:1px solid var(--line-strong);box-shadow:0 1px 2px rgba(17,18,22,.04);
  font-size:13px;font-weight:500;color:var(--ink-1);letter-spacing:-.005em;
}
.pill .liv{width:7px;height:7px;border-radius:50%;background:var(--live);box-shadow:0 0 0 3px rgba(31,171,90,.16)}

/* ============ hero ============ */
.hero{position:relative;padding-top:clamp(64px,9vw,110px);padding-bottom:clamp(56px,7vw,88px);overflow:hidden}
.hero::before{
  content:"";position:absolute;left:50%;top:-120px;width:min(1100px,120vw);height:720px;transform:translateX(-50%);
  background:radial-gradient(56% 60% at 50% 20%,rgba(47,107,237,.10),rgba(47,107,237,.03) 45%,transparent 72%);
  pointer-events:none;z-index:0;
}
.hero-in{position:relative;z-index:1;text-align:center;max-width:880px;margin:0 auto}
.hero h1{
  font-size:clamp(1.9rem,6.7vw,4.6rem);font-weight:600;letter-spacing:-.032em;line-height:1.08;
  color:var(--ink);margin:26px auto 0;max-width:16ch;
}
.hero h1 .thin{font-weight:400;color:var(--ink-1)}
.hero-sub{
  font-size:clamp(1.06rem,2vw,1.32rem);color:var(--ink-2);line-height:1.62;font-weight:400;
  max-width:600px;margin:26px auto 0;letter-spacing:-.006em;
}
.hero-cta{display:flex;gap:13px;justify-content:center;flex-wrap:wrap;margin-top:34px}
.hero-trust{
  display:flex;gap:22px;justify-content:center;flex-wrap:wrap;margin-top:26px;
  font-size:13px;color:var(--ink-3);font-weight:500;
}
.hero-trust span{display:inline-flex;align-items:center;gap:7px}
.hero-trust svg{width:14px;height:14px;color:var(--accent)}

/* hero shot */
.hero-stage{position:relative;z-index:1;margin:clamp(48px,7vw,84px) auto 0;max-width:1120px;perspective:1800px}
.hero-shot{
  transform-origin:center top;
  transform:perspective(1800px) rotateX(9deg) translateY(48px) scale(.985);
  opacity:0;will-change:transform,opacity;
  transition:transform 1.15s cubic-bezier(.16,1,.3,1) .12s,opacity 1s ease .12s;
}
.hero-shot.loaded{transform:perspective(1800px) rotateX(0) translateY(0) scale(1);opacity:1}

/* ============ browser frame ============ */
.frame{border-radius:var(--r);background:#fff;border:1px solid var(--line-strong);box-shadow:var(--shadow-hero);overflow:hidden}
.frame-bar{
  height:42px;display:flex;align-items:center;gap:8px;padding:0 16px;position:relative;
  border-bottom:1px solid var(--line);background:linear-gradient(#fdfdfe,#f6f7f9);
}
.tl{display:flex;gap:8px}
.tl i{width:11px;height:11px;border-radius:50%;display:block}
.tl i:nth-child(1){background:#f0605a}
.tl i:nth-child(2){background:#f7bd48}
.tl i:nth-child(3){background:#3fc65a}
.frame-title{
  position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);
  display:inline-flex;align-items:center;gap:8px;padding:4px 14px;border-radius:7px;
  background:rgba(17,18,22,.045);color:var(--ink-3);font-size:12px;font-weight:500;letter-spacing:-.005em;max-width:70%;
}
.frame-title svg{width:13px;height:13px;opacity:.7}
.frame-title .num{font-family:var(--mono);font-size:11px;color:var(--accent)}
.frame img{display:block;width:100%;height:auto}

/* media annotation */
.media{position:relative}
.anno{
  position:absolute;bottom:16px;left:16px;z-index:2;
  display:inline-flex;align-items:center;gap:9px;padding:8px 14px;border-radius:10px;
  background:rgba(255,255,255,.92);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
  border:1px solid var(--line);box-shadow:0 4px 16px rgba(17,18,22,.10);
  font-size:12.5px;font-weight:600;color:var(--ink);letter-spacing:-.01em;
}
.anno .dt{width:7px;height:7px;border-radius:2px;background:var(--accent)}

/* ============ features quick grid ============ */
.sec-head{max-width:640px}
.sec-head.center{max-width:680px;margin:0 auto;text-align:center}
.sec-head h2{font-size:clamp(1.8rem,3.6vw,2.9rem);letter-spacing:-.028em;margin-top:18px}
.sec-head p{margin-top:18px;font-size:clamp(1rem,1.5vw,1.15rem);color:var(--ink-2);line-height:1.62}
.sec-head.center .overline{justify-content:center}
.sec-head.center .overline::before{display:none}

.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:clamp(44px,5vw,64px)}
.fcard{
  background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:26px 24px 28px;
  box-shadow:var(--shadow-card);transition:transform .25s cubic-bezier(.2,.7,.3,1),box-shadow .25s,border-color .25s;
}
.fcard:hover{transform:translateY(-3px);box-shadow:var(--shadow-card-h);border-color:var(--line-strong)}
.fico{
  width:44px;height:44px;border-radius:11px;display:grid;place-items:center;margin-bottom:20px;
  background:var(--accent-soft);color:var(--accent);border:1px solid rgba(47,107,237,.14);
}
.fico svg{width:22px;height:22px}
.fcard h3{font-size:16.5px;letter-spacing:-.015em;margin-bottom:9px}
.fcard p{font-size:14px;color:var(--ink-2);line-height:1.6}

/* ============ feature rows ============ */
.rows{display:flex;flex-direction:column;gap:clamp(80px,11vw,150px)}
.frow{display:grid;grid-template-columns:1fr 1fr;gap:clamp(44px,6vw,88px);align-items:center}
.frow .ftext{max-width:460px}
.frow--rev .ftext{order:2}
.frow .fmedia{order:1}
.frow--rev .fmedia{order:0}
.idx{font-family:var(--serif);font-style:italic;font-size:clamp(2.6rem,4vw,3.4rem);line-height:1;color:var(--accent);opacity:.9;letter-spacing:0}
.ftext h2{font-size:clamp(1.7rem,3vw,2.5rem);letter-spacing:-.026em;margin-top:16px}
.ftext .lead{margin-top:20px;font-size:clamp(1rem,1.4vw,1.1rem);color:var(--ink-2);line-height:1.66}
.flist{list-style:none;padding:0;margin:28px 0 0;display:flex;flex-direction:column;gap:14px}
.flist li{display:flex;align-items:flex-start;gap:12px;font-size:15px;color:var(--ink-1);font-weight:500}
.flist .ck{
  flex:none;width:20px;height:20px;border-radius:6px;display:grid;place-items:center;margin-top:1px;
  background:var(--accent-soft);color:var(--accent);border:1px solid rgba(47,107,237,.16);
}
.flist .ck svg{width:12px;height:12px}
.frame--sm{box-shadow:0 2px 5px rgba(17,18,22,.05),0 16px 40px rgba(17,18,22,.09)}

/* security illustration */
.secfig{
  width:100%;border-radius:var(--r);border:1px solid var(--line);background:
    radial-gradient(120% 90% at 80% 0%,rgba(47,107,237,.05),transparent 60%),#fff;
  box-shadow:var(--shadow-card);padding:28px;
}
.secfig svg{width:100%;height:auto;display:block}

/* ============ download ============ */
.dl-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:clamp(44px,5vw,60px)}
.dl-card{
  position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--r);
  padding:34px 30px 30px;text-align:center;box-shadow:var(--shadow-card);
  transition:transform .25s cubic-bezier(.2,.7,.3,1),box-shadow .25s,border-color .25s;
  display:flex;flex-direction:column;align-items:center;
}
.dl-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-card-h);border-color:var(--line-strong)}
.os-ico{width:56px;height:56px;display:grid;place-items:center;margin-bottom:20px;color:var(--ink)}
.os-ico svg{width:44px;height:44px}
.dl-card h3{font-size:19px;letter-spacing:-.02em}
.dl-card .os-meta{margin-top:8px;font-size:13px;color:var(--ink-3);font-family:var(--mono);letter-spacing:-.01em}
.dl-card .btn{margin-top:24px;width:100%}
.dl-note{margin-top:34px;text-align:center;font-size:14px;color:var(--ink-3)}
.dl-note a{color:var(--accent);font-weight:500;border-bottom:1px solid rgba(47,107,237,.3);padding-bottom:1px;transition:border-color .2s}
.dl-note a:hover{border-color:var(--accent)}

/* ============ footer ============ */
.foot{border-top:1px solid var(--line);padding:60px 0 46px}
.foot-in{display:flex;justify-content:space-between;gap:40px;flex-wrap:wrap;align-items:flex-start}
.foot-brand{max-width:340px}
.foot-brand .brand{margin-bottom:16px}
.foot-brand p{font-size:14px;color:var(--ink-3);line-height:1.62}
.foot-links{display:flex;gap:56px;flex-wrap:wrap}
.foot-col h4{font-size:12px;text-transform:uppercase;letter-spacing:.14em;color:var(--ink-3);font-weight:600;margin-bottom:16px}
.foot-col a{display:block;font-size:14.5px;color:var(--ink-2);font-weight:500;padding:5px 0;transition:color .2s}
.foot-col a:hover{color:var(--ink)}
.foot-bottom{
  max-width:var(--maxw);margin:44px auto 0;padding:22px 28px 0;border-top:1px solid var(--line-2);
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:13px;color:var(--ink-3);
}
.foot-bottom .fb-tag{display:inline-flex;align-items:center;gap:8px}
.foot-bottom .fb-tag .liv{width:6px;height:6px;border-radius:50%;background:var(--live)}

/* ============ reveal ============ */
[data-reveal]{opacity:0;transform:translateY(24px);transition:opacity .8s cubic-bezier(.16,1,.3,1),transform .8s cubic-bezier(.16,1,.3,1)}
[data-reveal].is-in{opacity:1;transform:none}

/* ============ responsive ============ */
@media (max-width:960px){
  .grid4{grid-template-columns:repeat(2,1fr)}
  .frow{grid-template-columns:1fr;gap:36px}
  .frow .ftext,.frow--rev .ftext{order:0}
  .frow .fmedia,.frow--rev .fmedia{order:1}
  .frow .ftext{max-width:560px}
  .dl-grid{grid-template-columns:1fr;max-width:440px;margin-left:auto;margin-right:auto}
  .hero-shot,.hero-shot.loaded{transform:translateY(0) scale(1)!important}
}
@media (max-width:720px){
  .nav-links{display:none}
  .nav-in{gap:14px;height:60px}
  .wrap{padding:0 20px}
  .nav-in{padding:0 20px}
  .hero-trust{gap:14px 18px}
  .btn-lg{height:48px}
}
@media (max-width:520px){
  .grid4{grid-template-columns:1fr}
  .hero-cta{flex-direction:column;align-items:stretch}
  .hero-cta .btn{width:100%}
  .brand-txt span{display:none}
  .foot-bottom{flex-direction:column;gap:10px}
  .frame-title{display:none}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  [data-reveal]{opacity:1;transform:none;transition:none}
  .hero-shot{opacity:1;transform:none!important;transition:none}
}