/* ============================================================
   德苍官网 · 首页 demo
   单文件 / 内联 CSS 与 JS / 零外部依赖 / 零外部图片
   色板与字阶同源：专家意见/06-美术与视觉.md
   ============================================================ */
:root{
  /* 品牌色 */
  --gold:#D4A017; --gold-deep:#A87C10; --gold-light:#E8C25C; --gold-tint:#FBF3DC;
  --green:#2E9E5B; --green-deep:#1A6B3C; --green-light:#63C489; --green-tint:#E8F5ED;
  --tech:#35D0A0;
  /* 中性色 */
  --ink:#141A20; --txt:#38434F; --muted:#6B7784; --faint:#9AA6B2;
  --line:#E2E7EC; --bg-soft:#F5F7F9; --bg-tint:#EDF1F4;
  /* 深色场 */
  --dk-bg:#061512; --dk-panel:#0B211C; --dk-panel2:#113029;
  --dk-line:rgba(53,208,160,.20); --dk-txt:#C6D8D1; --dk-faint:#7E958C;
  /* 几何 */
  --wrap:1200px; --pad:24px; --r:10px; --r-lg:16px;
  --head-h:72px;
  --shadow-s:0 2px 10px rgba(20,26,32,.05);
  --shadow-m:0 10px 30px rgba(26,107,60,.10);
  --shadow-l:0 20px 50px rgba(20,26,32,.12);
  /* 流体字阶 */
  --fs-h1:clamp(28px,5.0vw,54px);
  --fs-h2:clamp(22px,2.6vw,36px);
  --fs-h3:clamp(16px,1.4vw,19px);
  --fs-body:clamp(14px,1.05vw,16px);
  --sec-y:clamp(56px,7vw,104px);
}
*,*::before,*::after{ box-sizing:border-box; margin:0; padding:0; }
html{ -webkit-text-size-adjust:100%; scroll-behavior:smooth; scroll-padding-top:88px; }
body{
  font-family:"Microsoft YaHei","PingFang SC","Source Han Sans SC",sans-serif;
  font-size:var(--fs-body); line-height:1.85; color:var(--txt);
  background:#fff; overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img,svg{ max-width:100%; }
a{ color:inherit; text-decoration:none; }
ul{ list-style:none; }
button{ font:inherit; color:inherit; background:none; border:0; cursor:pointer; }
.num{ font-variant-numeric:tabular-nums; font-feature-settings:"tnum" 1; }
:focus-visible{ outline:2px solid var(--gold); outline-offset:3px; border-radius:4px; }

.wrap{ width:100%; max-width:var(--wrap); margin:0 auto; padding:0 var(--pad); }
.skip{ position:absolute; left:-9999px; top:0; z-index:999;
  background:var(--gold); color:#101010; padding:10px 18px; font-weight:700; }
.skip:focus{ left:12px; top:12px; }
.sr{ position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; }

/* ---------- 通用文字块 ---------- */
.eyebrow{
  display:inline-flex; align-items:center; gap:8px;
  font-size:12px; font-weight:700; letter-spacing:2px;
  color:var(--gold-deep); text-transform:uppercase;
}
.eyebrow::before{ content:""; width:22px; height:2px; background:var(--gold); }
.dark .eyebrow{ color:var(--gold-light); }
h2.sec-t{
  font-size:var(--fs-h2); font-weight:800; line-height:1.3; letter-spacing:1px;
  color:var(--green-deep); margin:14px 0 8px;
}
.dark h2.sec-t{ color:#fff; }
.sec-en{ font-size:12px; font-weight:600; letter-spacing:3px; color:var(--faint); text-transform:uppercase; }
.sec-lead{ max-width:760px; color:var(--muted); margin-top:14px; }
.sec-head{ margin-bottom:clamp(28px,3.4vw,48px); }
.sec-head.center{ text-align:center; }
.sec-head.center .sec-lead{ margin-left:auto; margin-right:auto; }
section.band{ padding:var(--sec-y) 0; }
section.soft{ background:var(--bg-soft); }
.disc{
  margin-top:22px; padding:12px 16px; border-left:3px solid var(--line);
  font-size:12.5px; line-height:1.75; color:var(--muted); background:#fff;
  border-radius:0 6px 6px 0;
}
.dark .disc{ background:rgba(255,255,255,.03); border-left-color:var(--dk-line); color:var(--dk-faint); }

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  min-height:46px; padding:0 26px; border-radius:8px;
  font-size:15px; font-weight:700; letter-spacing:.5px;
  transition:transform .2s, box-shadow .2s, background .2s, color .2s, border-color .2s;
  white-space:nowrap;
}
.btn-gold{ background:linear-gradient(135deg,#E0AE28,var(--gold)); color:#1B1403;
  box-shadow:0 6px 18px rgba(212,160,23,.32); }
.btn-gold:hover{ transform:translateY(-2px); box-shadow:0 10px 24px rgba(212,160,23,.42); }
.btn-ghost{ border:1.5px solid rgba(212,160,23,.55); color:var(--gold-light); }
.btn-ghost:hover{ border-color:var(--gold); background:rgba(212,160,23,.10); transform:translateY(-2px); }
.btn-green{ background:var(--green-deep); color:#fff; box-shadow:0 6px 18px rgba(26,107,60,.24); }
.btn-green:hover{ transform:translateY(-2px); background:#155832; }
.btn-line{ border:1.5px solid var(--line); color:var(--green-deep); background:#fff; }
.btn-line:hover{ border-color:var(--green); color:var(--green-deep); transform:translateY(-2px); }
.btn-sm{ min-height:38px; padding:0 18px; font-size:13.5px; }
.arrow{ transition:transform .2s; }
.btn:hover .arrow{ transform:translateX(3px); }

/* ---------- 线稿图标 ---------- */
.ic{ width:40px; height:40px; flex:0 0 auto;
  fill:none; stroke:var(--green-deep); stroke-width:2;
  stroke-linecap:round; stroke-linejoin:round; }
.ic .hi{ stroke:var(--gold); }
.ic .fill{ fill:var(--gold); stroke:none; }
.ic-sm{ width:26px; height:26px; }
.dark .ic{ stroke:var(--tech); }
.dark .ic .hi{ stroke:var(--gold-light); }
.dark .ic .fill{ fill:var(--gold-light); }

/* ============================================================
   顶部导航（吸顶）
   ============================================================ */
.site-head{
  position:sticky; top:0; z-index:100;
  background:rgba(6,21,18,.92);
  -webkit-backdrop-filter:blur(10px); backdrop-filter:blur(10px);
  border-bottom:1px solid rgba(53,208,160,.14);
  transition:background .3s, box-shadow .3s, border-color .3s;
}
.site-head.stuck{ background:rgba(6,21,18,.98); box-shadow:0 6px 24px rgba(0,0,0,.28); }
.head-in{ display:flex; align-items:center; gap:20px; height:var(--head-h); }

.logo{ display:flex; align-items:center; gap:9px; flex:0 0 auto; }
.logo-d{
  width:28px; height:28px; border:2px solid var(--gold); border-radius:5px;
  display:flex; align-items:center; justify-content:center;
  font-size:16px; font-weight:900; color:var(--gold); line-height:1;
}
.logo-w{ font-size:21px; font-weight:900; letter-spacing:3px; color:var(--gold); line-height:1; }
.logo-cn{ font-size:12px; font-weight:600; letter-spacing:3px; color:var(--dk-faint);
  padding-left:9px; margin-left:2px; border-left:1px solid rgba(53,208,160,.28); }

.nav{ margin-left:auto; }
.nav ul{ display:flex; align-items:center; gap:4px; }
.nav a{
  position:relative; display:block; padding:9px 13px; border-radius:6px;
  font-size:14.5px; font-weight:600; color:var(--dk-txt); transition:color .2s, background .2s;
}
.nav a::after{
  content:""; position:absolute; left:13px; right:13px; bottom:4px; height:2px;
  background:var(--gold); transform:scaleX(0); transform-origin:left; transition:transform .25s;
}
.nav a:hover{ color:#fff; }
.nav a:hover::after,.nav a[aria-current="page"]::after{ transform:scaleX(1); }
.nav a[aria-current="page"]{ color:var(--gold-light); }
.nav .m-cta{ display:none; }          /* 仅移动端抽屉里出现 */
.head-cta{ flex:0 0 auto; margin-left:8px; }
.burger{
  display:none; width:44px; height:44px; margin-left:auto;
  align-items:center; justify-content:center; border-radius:8px;
  border:1px solid rgba(53,208,160,.28);
}
.burger span{ display:block; width:19px; height:2px; background:var(--gold); border-radius:2px;
  position:relative; transition:transform .25s, background .25s; }
.burger span::before,.burger span::after{
  content:""; position:absolute; left:0; width:19px; height:2px; background:var(--gold); border-radius:2px;
  transition:transform .25s, opacity .2s;
}
.burger span::before{ top:-6px; } .burger span::after{ top:6px; }
body.nav-open .burger span{ background:transparent; }
body.nav-open .burger span::before{ transform:translateY(6px) rotate(45deg); }
body.nav-open .burger span::after{ transform:translateY(-6px) rotate(-45deg); }

/* ============================================================
   屏 1 · Hero
   ============================================================ */
.hero{
  position:relative; overflow:hidden; color:var(--dk-txt);
  background:
    radial-gradient(90% 70% at 82% 6%, #0E3128 0%, rgba(6,21,18,0) 62%),
    radial-gradient(70% 60% at 8% 96%, #0B2A22 0%, rgba(6,21,18,0) 60%),
    var(--dk-bg);
  padding:clamp(56px,7vw,96px) 0 clamp(48px,6vw,84px);
}
.hero::before{
  content:""; position:absolute; inset:0; pointer-events:none;
  background-image:
    linear-gradient(rgba(53,208,160,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(53,208,160,.05) 1px,transparent 1px);
  background-size:52px 52px;
  -webkit-mask-image:radial-gradient(80% 70% at 50% 40%,#000 0%,transparent 78%);
  mask-image:radial-gradient(80% 70% at 50% 40%,#000 0%,transparent 78%);
}
.hero::after{
  content:""; position:absolute; width:420px; height:420px; right:-90px; top:-140px;
  background:radial-gradient(circle,rgba(212,160,23,.16) 0%,transparent 68%);
  border-radius:50%; pointer-events:none;
}
.hero-in{ position:relative; z-index:2; display:grid; grid-template-columns:minmax(0,1.08fr) minmax(0,.92fr);
  gap:clamp(28px,4vw,64px); align-items:center; }
.hero h1{
  font-size:var(--fs-h1); font-weight:900; line-height:1.18; letter-spacing:4px;
  color:#fff; margin:16px 0 12px;
}
.hero h1 .accent{ color:var(--gold); }
.hero-en{ font-size:clamp(13px,1.3vw,17px); font-weight:600; letter-spacing:3px; color:var(--gold-light); }
.hero-lead{ max-width:520px; margin-top:20px; color:var(--dk-txt); opacity:.92; }
.chips{ display:flex; flex-wrap:wrap; gap:9px; margin-top:22px; }
.chip{
  display:inline-flex; align-items:center; gap:6px;
  padding:6px 13px; border-radius:999px; font-size:13px; font-weight:600;
  color:var(--dk-txt); background:rgba(53,208,160,.07); border:1px solid var(--dk-line);
}
.chip::before{ content:""; width:5px; height:5px; border-radius:50%; background:var(--tech); }
.hero-btns{ display:flex; flex-wrap:wrap; gap:14px; margin-top:32px; }
.hero-stats{
  display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:clamp(14px,2vw,28px);
  margin-top:38px; padding-top:26px; border-top:1px solid var(--dk-line);
}
.stat b{ display:block; font-size:clamp(20px,2.2vw,28px); font-weight:900; color:var(--tech); line-height:1.2; }
.stat span{ display:block; font-size:12.5px; color:var(--dk-faint); margin-top:4px; letter-spacing:.5px; }
.hero-art{ position:relative; }
.hero-art svg{ width:100%; height:auto; display:block; }
.flow-dash{ stroke-dasharray:7 7; animation:dashmove 1.6s linear infinite; }
@keyframes dashmove{ to{ stroke-dashoffset:-28; } }
.pulse{ animation:pulse 2.4s ease-in-out infinite; transform-origin:center; }
.pulse.d2{ animation-delay:.5s; } .pulse.d3{ animation-delay:1s; } .pulse.d4{ animation-delay:1.5s; }
@keyframes pulse{ 0%,100%{ opacity:.35; } 50%{ opacity:1; } }

/* ============================================================
   屏 2 · 三大业务线
   ============================================================ */
.line-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:24px; }
.line-card{
  position:relative; background:#fff; border:1px solid var(--line); border-radius:var(--r-lg);
  padding:32px 28px 26px; box-shadow:var(--shadow-s);
  transition:transform .28s, box-shadow .28s, border-color .28s;
  display:flex; flex-direction:column;
}
.line-card::before{
  content:""; position:absolute; left:0; right:0; top:0; height:3px; border-radius:var(--r-lg) var(--r-lg) 0 0;
  background:linear-gradient(90deg,var(--green),var(--tech)); transform:scaleX(0); transform-origin:left;
  transition:transform .32s;
}
.line-card:hover{ transform:translateY(-5px); box-shadow:var(--shadow-m); border-color:#CFE7D9; }
.line-card:hover::before{ transform:scaleX(1); }
.line-ic{
  width:62px; height:62px; border-radius:14px; margin-bottom:18px;
  display:flex; align-items:center; justify-content:center;
  background:var(--green-tint); border:1px solid #CFE7D9;
}
.line-card h3{ font-size:var(--fs-h3); font-weight:800; color:var(--green-deep); letter-spacing:.5px; }
.line-card .kick{ margin:8px 0 16px; color:var(--muted); font-size:14px; }
.bl{ display:flex; gap:10px; align-items:flex-start; font-size:14px; line-height:1.75; margin-bottom:9px; }
.bl::before{ content:""; flex:0 0 auto; width:7px; height:7px; margin-top:9px;
  background:var(--green); transform:rotate(45deg); }
.line-more{ margin-top:auto; padding-top:18px; font-size:13.5px; font-weight:700; color:var(--gold-deep); }
.line-more .arrow{ display:inline-block; }
.line-card:hover .line-more .arrow{ transform:translateX(4px); }

/* ============================================================
   屏 3 · 平台能力
   ============================================================ */
.plat-grid{ display:grid; grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr); gap:clamp(28px,3.6vw,56px); align-items:start; }
.stack{ display:flex; flex-direction:column; gap:10px; }
.layer{
  border:1px solid var(--line); border-radius:12px; background:#fff; padding:16px 20px;
  display:flex; align-items:center; gap:16px; box-shadow:var(--shadow-s);
}
.layer .lb{
  flex:0 0 84px; font-size:12px; font-weight:800; letter-spacing:1px; color:var(--muted);
  border-right:1px solid var(--line); padding-right:14px;
}
.layer .lc{ font-size:13.5px; line-height:1.7; }
.layer .lc b{ color:var(--green-deep); }
.layer.core{
  background:linear-gradient(135deg,#FDF8EA,#FBF3DC); border-color:var(--gold);
  box-shadow:0 8px 24px rgba(212,160,23,.16);
}
.layer.core .lb{ color:var(--gold-deep); border-right-color:rgba(212,160,23,.4); }
.layer.apps{ background:var(--green-tint); border-color:#CFE7D9; }
.app-pills{ display:flex; flex-wrap:wrap; gap:8px; }
.pill{
  font-size:12.5px; font-weight:700; padding:5px 12px; border-radius:999px;
  background:#fff; border:1px solid #CFE7D9; color:var(--green-deep);
}
.pill.gold{ background:var(--gold-tint); border-color:rgba(212,160,23,.5); color:var(--gold-deep); }
.layer-arrow{ text-align:center; color:var(--faint); font-size:12px; line-height:1; }
.deploy{ display:flex; flex-direction:column; gap:14px; }
.dep{
  border:1px solid var(--line); border-radius:12px; padding:18px 20px; background:#fff;
  box-shadow:var(--shadow-s); transition:transform .25s, border-color .25s;
}
.dep:hover{ transform:translateX(4px); border-color:#CFE7D9; }
.dep .tag{
  display:inline-block; font-size:12px; font-weight:800; letter-spacing:1px;
  color:#fff; background:var(--green-deep); border-radius:5px; padding:2px 9px; margin-bottom:8px;
}
.dep h3{ font-size:15px; font-weight:800; color:var(--ink); margin-bottom:4px; }
.dep p{ font-size:13.5px; color:var(--muted); line-height:1.7; }

/* ============================================================
   屏 4 · 产品矩阵
   ============================================================ */
.tabs{ display:flex; flex-wrap:wrap; gap:10px; margin-bottom:28px; }
.tab{
  min-height:42px; padding:0 20px; border-radius:8px; font-size:14.5px; font-weight:700;
  border:1px solid var(--line); background:#fff; color:var(--muted);
  transition:all .22s;
}
.tab:hover{ border-color:var(--green-light); color:var(--green-deep); }
.tab[aria-selected="true"]{
  background:var(--green-deep); border-color:var(--green-deep); color:#fff;
  box-shadow:0 6px 16px rgba(26,107,60,.22);
}
.panel[hidden]{ display:none; }
.prod-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:18px; }
.prod{
  background:#fff; border:1px solid var(--line); border-radius:12px; padding:20px 18px;
  display:flex; flex-direction:column; gap:10px;
  transition:transform .25s, box-shadow .25s, border-color .25s;
}
.prod:hover{ transform:translateY(-4px); box-shadow:var(--shadow-m); border-color:#CFE7D9; }
.prod-top{
  height:74px; border-radius:9px; margin:-4px -2px 4px;
  display:flex; align-items:center; justify-content:center;
  background:linear-gradient(160deg,#FBFCFB,#EFF6F2); border:1px solid #EAF0EC;
}
.prod-model{ font-size:15px; font-weight:800; letter-spacing:.6px; color:var(--green-deep); }
.prod-name{ font-size:13px; color:var(--txt); line-height:1.6; min-height:42px; }
.meta{ display:flex; flex-wrap:wrap; gap:6px; margin-top:auto; }
.meta span{
  font-size:11.5px; font-weight:600; color:var(--muted);
  background:var(--bg-tint); border-radius:5px; padding:3px 8px;
}
.prod-note{
  margin-top:20px; font-size:13.5px; color:var(--muted); line-height:1.8;
  background:#fff; border:1px dashed var(--line); border-radius:10px; padding:14px 18px;
}
.prod-note b{ color:var(--green-deep); }
.matrix-foot{ display:flex; flex-wrap:wrap; gap:14px; align-items:center; margin-top:28px; }

/* ============================================================
   屏 5 · 应用场景
   ============================================================ */
.scene-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.scene{
  background:#fff; border:1px solid var(--line); border-radius:12px; padding:26px 24px;
  transition:transform .25s, box-shadow .25s;
}
.scene:hover{ transform:translateY(-4px); box-shadow:var(--shadow-m); }
.scene h3{ font-size:16px; font-weight:800; color:var(--ink); margin:14px 0 6px; }
.scene p{ font-size:13.5px; color:var(--muted); line-height:1.75; }
.scene .cfg{
  margin-top:14px; padding-top:12px; border-top:1px dashed var(--line);
  font-size:12.5px; color:var(--green-deep); font-weight:600; line-height:1.7;
}

/* ============================================================
   屏 6 · 差异点
   ============================================================ */
.why-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:clamp(18px,2.4vw,32px); }
.why-i{ border-top:2px solid rgba(212,160,23,.35); padding-top:20px; }
.why-i .no{ font-size:26px; font-weight:900; color:var(--gold); letter-spacing:1px; line-height:1; }
.why-i h3{ font-size:15.5px; font-weight:800; color:#fff; margin:12px 0 8px; }
.why-i p{ font-size:13.5px; color:var(--dk-faint); line-height:1.8; }

/* ============================================================
   屏 7 · 服务
   ============================================================ */
.svc-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:20px; }
.svc{ background:#fff; border:1px solid var(--line); border-radius:12px; padding:26px 22px;
  transition:transform .25s, box-shadow .25s; }
.svc:hover{ transform:translateY(-4px); box-shadow:var(--shadow-m); }
.svc h3{ font-size:15.5px; font-weight:800; color:var(--green-deep); margin:14px 0 4px; }
.svc .en{ font-size:11px; font-weight:600; letter-spacing:1.4px; color:var(--faint); text-transform:uppercase; }
.svc p{ font-size:13.5px; color:var(--muted); line-height:1.8; margin-top:10px; }

/* ============================================================
   屏 8 · 转化条 + 页脚
   ============================================================ */
.band-cta{
  background:linear-gradient(120deg,#1A6B3C 0%,#0F4A2A 52%,#0B2A22 100%);
  color:#fff; position:relative; overflow:hidden;
}
.band-cta::after{
  content:""; position:absolute; right:-60px; top:-60px; width:320px; height:320px; border-radius:50%;
  background:radial-gradient(circle,rgba(212,160,23,.22),transparent 68%);
}
.band-in{ position:relative; z-index:2; display:flex; flex-wrap:wrap; gap:26px;
  align-items:center; justify-content:space-between; }
.band-in h2{ font-size:clamp(20px,2.4vw,32px); font-weight:800; letter-spacing:1px; }
.band-in p{ margin-top:10px; color:rgba(255,255,255,.82); max-width:640px; font-size:14.5px; }

.site-foot{ background:var(--dk-bg); color:var(--dk-faint); padding:clamp(44px,5vw,72px) 0 0; }
.foot-grid{ display:grid; grid-template-columns:1.6fr 1fr 1fr 1.3fr; gap:clamp(24px,3vw,48px); }
.foot-brand .logo{ margin-bottom:16px; }
.foot-brand p{ font-size:13px; line-height:1.9; }
.foot-brand .en{ font-size:11.5px; letter-spacing:.6px; color:#5F7871; margin-top:6px; }
.foot h3{ font-size:14px; font-weight:800; color:var(--dk-txt); margin-bottom:14px; letter-spacing:1px; }
.foot li{ margin-bottom:9px; font-size:13.5px; }
.foot a:hover{ color:var(--gold-light); }
.foot .tbd{ color:var(--gold-light); opacity:.85; }
.foot-bot{
  margin-top:clamp(32px,4vw,52px); border-top:1px solid var(--dk-line);
  padding:20px 0 26px; display:flex; flex-wrap:wrap; gap:8px 22px;
  align-items:center; justify-content:center; font-size:12.5px; color:#6E8880;
}
.foot-bot a{ color:#87A29A; }
.foot-bot a:hover{ color:var(--gold-light); text-decoration:underline; }
.foot-bot .gongan{ display:inline-flex; align-items:center; gap:6px; }
.foot-disc{ font-size:12px; line-height:1.8; color:#5F7871; text-align:center;
  padding-bottom:24px; max-width:920px; margin:0 auto; }

/* 回到顶部 */
.totop{
  position:fixed; right:20px; bottom:24px; z-index:90;
  width:46px; height:46px; border-radius:50%; background:var(--green-deep); color:#fff;
  display:flex; align-items:center; justify-content:center;
  box-shadow:0 8px 22px rgba(26,107,60,.34);
  opacity:0; visibility:hidden; transform:translateY(10px); transition:all .28s;
}
.totop.show{ opacity:1; visibility:visible; transform:none; }
.totop:hover{ background:var(--green); }

/* ---------- 滚动淡入（无 JS 时不隐藏） ---------- */
.js .rv{ opacity:0; transform:translateY(20px); transition:opacity .7s ease, transform .7s cubic-bezier(.22,.9,.28,1); }
.js .rv.in{ opacity:1; transform:none; }
.js .rv.d1{ transition-delay:.08s; } .js .rv.d2{ transition-delay:.16s; }
.js .rv.d3{ transition-delay:.24s; } .js .rv.d4{ transition-delay:.32s; }

/* ============================================================
   响应式：1200 / 992 / 768 / 480
   ============================================================ */
@media (max-width:1199px){
  :root{ --wrap:100%; --pad:22px; }
  .prod-grid{ grid-template-columns:repeat(3,1fr); }
  .hero-in{ grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr); }
  .nav a{ padding:9px 10px; font-size:14px; }
}
@media (max-width:991px){
  /* 导航折叠为汉堡（桌面横排在 992px 以下会换行，必须提前收起） */
  .burger{ display:flex; }
  .head-cta{ display:none; }
  .logo-cn{ display:none; }
  /* 抽屉用 opacity + 纵向位移，不用 translateX（横向位移会撑出文档宽度，
     而 body 的 overflow-x:hidden 会向视口传播、并不能裁掉它 —— 会造成整页横向滚动） */
  .nav{
    position:fixed; left:0; right:0; top:var(--head-h); bottom:0;
    background:rgba(6,21,18,.985);
    -webkit-backdrop-filter:blur(12px); backdrop-filter:blur(12px);
    padding:14px var(--pad) 30px; overflow-y:auto; margin-left:0;
    opacity:0; visibility:hidden; pointer-events:none; transform:translateY(-10px);
    transition:opacity .26s ease, transform .26s ease, visibility .26s;
  }
  body.nav-open{ overflow:hidden; }
  body.nav-open .nav{ opacity:1; visibility:visible; pointer-events:auto; transform:none; }
  .nav ul{ flex-direction:column; align-items:stretch; gap:2px; }
  .nav a{ padding:15px 6px; font-size:16px; border-bottom:1px solid rgba(53,208,160,.10); border-radius:0; }
  .nav a::after{ display:none; }
  .nav .m-cta{ display:block; margin-top:22px; }
  .nav .m-cta .btn{ width:100%; }

  .hero-in{ grid-template-columns:1fr; gap:34px; }
  .hero-art{ order:2; max-width:520px; margin:0 auto; width:100%; }
  .hero-stats{ max-width:620px; }
  .why-grid{ grid-template-columns:repeat(2,1fr); }
  .svc-grid{ grid-template-columns:repeat(2,1fr); }
  .scene-grid{ grid-template-columns:repeat(2,1fr); }
  .plat-grid{ grid-template-columns:1fr; }
  .foot-grid{ grid-template-columns:1fr 1fr; }
}
@media (max-width:767px){
  :root{ --pad:18px; --head-h:62px; }
  html{ scroll-padding-top:74px; }
  .hero h1{ letter-spacing:2px; }
  .line-grid{ grid-template-columns:1fr; }
  .prod-grid{ grid-template-columns:repeat(2,1fr); }
  .foot-grid{ grid-template-columns:1fr; gap:28px; }
  .band-in{ flex-direction:column; align-items:flex-start; }
  .layer{ flex-direction:column; align-items:flex-start; gap:8px; }
  .layer .lb{ flex:none; border-right:0; border-bottom:1px solid var(--line); padding:0 0 6px; width:100%; }
}
@media (max-width:479px){
  :root{ --pad:16px; }
  .hero h1{ letter-spacing:1px; }
  .hero-btns{ flex-direction:column; align-items:stretch; }
  .hero-btns .btn{ width:100%; }
  .hero-stats{ grid-template-columns:1fr; gap:14px; }
  .prod-grid{ grid-template-columns:1fr; }
  .scene-grid,.svc-grid,.why-grid{ grid-template-columns:1fr; }
  .prod-name{ min-height:0; }
  .tabs{ gap:8px; }
  .tab{ flex:1 1 46%; padding:0 10px; font-size:13.5px; }
  .totop{ right:14px; bottom:16px; width:42px; height:42px; }
}
@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ animation-duration:.001ms !important; animation-iteration-count:1 !important;
    transition-duration:.001ms !important; }
  .js .rv{ opacity:1 !important; transform:none !important; }
}
@media print{
  .site-head,.totop,.band-cta{ display:none; }
  body{ color:#000; }
}