:root{
    --bg:#ffffff;
    --bg-alt:#f5f7fb;
    --surface:#ffffff;
    --ink:#0b1f3a;
    --ink-dim:#5b6b82;
    --line:#e6eaf0;
    --accent:#1f6feb;
    --accent-soft:#e8f0ff;
    --accent-2:#ff6b3d;
    --panel-dark:#0b1f3a;
    --panel-dark-2:#132b4d;
    --shadow:rgba(11,31,58,.12);
    --flow-opacity:0;
  }
  html[data-theme="dark"]{
    --bg:#070b10;
    --bg-alt:#0c131b;
    --surface:#0f1720;
    --ink:#eef1f5;
    --ink-dim:#8b96a3;
    --line:rgba(255,255,255,.08);
    --accent:#3fb7ff;
    --accent-soft:rgba(63,183,255,.14);
    --accent-2:#cdae72;
    --panel-dark:#0c131b;
    --panel-dark-2:#0f1720;
    --shadow:rgba(0,0,0,.55);
    --flow-opacity:0.5;
  }
  *{margin:0;padding:0;box-sizing:border-box;}
  html{scroll-behavior:smooth;}
  body{
    font-family:"Noto Sans SC","Manrope",sans-serif;color:var(--ink);background:var(--bg);
    transition:background .5s ease, color .5s ease;
  }
  .en{font-family:"Manrope","Noto Sans SC",sans-serif;}
  a{text-decoration:none;color:inherit;}
  ul{list-style:none;}
  svg{display:block;}
  .container{max-width:1240px;margin:0 auto;padding:0 40px;}
  section, header, footer{transition:background .5s ease, border-color .5s ease, box-shadow .3s ease;}

  /* ============ NAV ============ */
  header{
    position:sticky;top:0;z-index:100;background:var(--bg);
    border-bottom:1px solid var(--line);
  }
  header.scrolled{box-shadow:0 8px 24px var(--shadow);}
  .nav-inner{
    max-width:1640px;margin:0 auto;padding:0 40px;
    display:flex;align-items:center;justify-content:space-between;height:76px;
  }
  .logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;}
  .logo-img{height:34px;width:auto;display:block;filter:brightness(0);}
  html[data-theme="dark"] .logo-img{filter:brightness(0) invert(1);}
  .main-nav{display:flex;align-items:center;gap:6px;height:100%;}
  .nav-item{position:relative;height:100%;display:flex;align-items:center;}
  .nav-item > a, .nav-item > span{
    padding:0 18px;height:100%;display:flex;align-items:center;gap:6px;
    font-size:14.5px;font-weight:600;color:var(--ink);cursor:pointer;position:relative;
  }
  .nav-item > a::after, .nav-item > span::after{
    content:"";position:absolute;left:18px;right:18px;bottom:0;height:2px;background:var(--accent);
    transform:scaleX(0);transform-origin:left;transition:transform .25s ease;
  }
  .nav-item:hover > a::after, .nav-item:hover > span::after{transform:scaleX(1);}
  .nav-item.active > a{color:var(--accent);}
  .nav-item.active > a::after{transform:scaleX(1);}
  .nav-item .caret{width:8px;height:8px;border-right:1.6px solid var(--ink-dim);border-bottom:1.6px solid var(--ink-dim);transform:rotate(45deg);margin-top:-3px;transition:transform .2s;}
  .nav-item:hover .caret{transform:rotate(-135deg);margin-top:3px;}
  .nav-item:hover > a, .nav-item:hover > span{color:var(--accent);}

  .mega{
    position:absolute;top:100%;left:50%;transform:translateX(-50%) translateY(4px);
    background:var(--surface);border:1px solid var(--line);border-radius:10px;
    box-shadow:0 20px 50px var(--shadow);
    padding:28px;display:flex;gap:36px;z-index:50;
    opacity:0;visibility:hidden;transition:opacity .22s ease, transform .22s ease, visibility .22s;
  }
  .nav-item:hover .mega{opacity:1;visibility:visible;transform:translateX(-50%) translateY(10px);}
  .mega-col{min-width:190px;}
  .mega-col h4{font-size:12px;color:var(--ink-dim);letter-spacing:1px;margin-bottom:14px;font-weight:700;}
  .mega-col a{display:block;font-size:14px;padding:7px 0;color:var(--ink);font-weight:500;transition:color .2s;}
  .mega-col a:hover{color:var(--accent);}
  .mega-col a .tag{display:block;font-size:12px;color:var(--ink-dim);font-weight:400;margin-top:2px;}
  .mega.products{gap:6px;}
  .prod-mini{width:210px;padding:14px;border-radius:8px;transition:background .2s;display:flex;gap:12px;align-items:flex-start;}
  .prod-mini:hover{background:var(--bg-alt);}
  .prod-mini svg{flex-shrink:0;margin-top:2px;}
  .prod-mini .en{color:var(--accent);font-size:11.5px;letter-spacing:1px;font-weight:700;}
  .prod-mini h5{font-size:15px;margin:6px 0 4px;font-weight:700;}
  .prod-mini p{font-size:12.5px;color:var(--ink-dim);line-height:1.6;}

  .nav-cta{display:flex;align-items:center;gap:16px;}
  .theme-toggle{
    width:38px;height:38px;border-radius:50%;border:1px solid var(--line);
    display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--ink);
    background:var(--surface);transition:border-color .2s;
  }
  .theme-toggle:hover{border-color:var(--accent);}
  .lang-btn{
    display:inline-flex;align-items:center;height:36px;padding:0 14px;border-radius:18px;
    border:1px solid var(--line);background:var(--surface);color:var(--ink);
    font-size:13px;font-weight:600;font-family:"Noto Sans SC","Manrope",sans-serif;
    cursor:pointer;text-decoration:none;white-space:nowrap;outline:none;
    transition:border-color .2s,color .2s;
  }
  .lang-btn:hover,.lang-btn:focus{border-color:var(--accent);color:var(--accent);}
  .lang-select:hover,.lang-select:focus{border-color:var(--accent);}
  /* ============ contact qr modal ============ */
  .qr-modal{position:fixed;inset:0;z-index:200;display:flex;align-items:center;justify-content:center;padding:24px;opacity:0;pointer-events:none;transition:opacity .3s ease;}
  .qr-modal.open{opacity:1;pointer-events:auto;}
  .qr-modal-backdrop{position:absolute;inset:0;background:rgba(8,18,36,.55);backdrop-filter:blur(6px);}
  .qr-modal-card{position:relative;width:100%;max-width:420px;background:var(--surface);border:1px solid var(--line);border-radius:20px;box-shadow:0 30px 80px rgba(8,20,40,.28);transform:translateY(26px) scale(.96);transition:transform .35s cubic-bezier(.2,.9,.3,1.15);overflow:hidden;max-height:calc(100vh - 48px);overflow-y:auto;}
  .qr-modal.open .qr-modal-card{transform:translateY(0) scale(1);}
  .qr-modal-head{position:relative;background:linear-gradient(135deg,#1f6feb,#3b9bff);padding:26px 30px 24px;color:#fff;}
  .qr-modal-head .qr-brand{font-size:10.5px;font-weight:800;letter-spacing:2px;opacity:.75;margin-bottom:10px;text-transform:uppercase;}
  .qr-modal-head h3{font-size:21px;font-weight:800;margin-bottom:6px;}
  .qr-modal-head p{font-size:12.5px;opacity:.8;line-height:1.6;}
  .qr-modal-head::after{content:"";position:absolute;right:-30px;top:-40px;width:140px;height:140px;border-radius:50%;background:rgba(255,255,255,.08);}
  .qr-modal-close{position:absolute;top:14px;right:14px;width:30px;height:30px;border-radius:50%;background:rgba(255,255,255,.16);border:none;color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:background .2s;z-index:2;}
  .qr-modal-close:hover{background:rgba(255,255,255,.3);}
  .qr-modal-body{padding:10px 26px 4px;}
  .qr-codes{display:grid;grid-template-columns:1fr 1fr;gap:14px;padding:14px 0 6px;}
  .qr-code{border:1px solid var(--line);border-radius:12px;padding:12px;background:var(--bg-alt);text-align:center;transition:border-color .2s,transform .2s;}
  .qr-code:hover{border-color:var(--accent);transform:translateY(-2px);}
  .qr-code-img{width:100%;aspect-ratio:1/1;border-radius:8px;overflow:hidden;background:#fff;display:flex;align-items:center;justify-content:center;}
  .qr-code-img img{width:100%;height:100%;object-fit:contain;display:block;}
  .qr-code-label{font-size:12px;font-weight:700;color:var(--ink);margin-top:8px;letter-spacing:.5px;}
  .qr-code-label small{display:block;font-size:10.5px;font-weight:400;color:var(--ink-dim);margin-top:2px;}
  .qr-item{display:flex;gap:14px;align-items:flex-start;padding:16px 0;border-bottom:1px solid var(--line);}
  .qr-item:last-child{border-bottom:none;}
  .qr-item-ico{width:38px;height:38px;border-radius:10px;background:var(--accent-soft);color:var(--accent);display:flex;align-items:center;justify-content:center;flex-shrink:0;}
  .qr-item-ico svg{width:18px;height:18px;}
  .qr-item-label{font-size:11px;font-weight:700;letter-spacing:1.5px;color:var(--ink-dim);margin-bottom:4px;}
  .qr-item-val{font-size:13.5px;font-weight:600;color:var(--ink);line-height:1.65;word-break:break-all;}
  .qr-item-val a{color:var(--accent);text-decoration:none;transition:opacity .2s;}
  .qr-item-val a:hover{opacity:.75;}
  .qr-modal-foot{padding:6px 26px 24px;}
  .qr-modal-foot .btn{width:100%;justify-content:center;}
  .menu-toggle{display:none;width:38px;height:38px;border-radius:8px;border:1px solid var(--line);align-items:center;justify-content:center;cursor:pointer;color:var(--ink);}
  .mobile-back{display:none;width:38px;height:38px;border-radius:50%;border:1px solid var(--line);align-items:center;justify-content:center;cursor:pointer;color:var(--ink);flex-shrink:0;}
  .mobile-back:hover{border-color:var(--accent);color:var(--accent);}
  .btn{
    display:inline-flex;align-items:center;gap:8px;font-weight:700;font-size:14px;
    padding:11px 22px;border-radius:6px;transition:all .2s ease;cursor:pointer;
  }
  .btn svg{transition:transform .2s ease;}
  .btn:hover svg{transform:translateX(3px);}
  .btn-primary{background:var(--panel-dark);color:#fff;}
  .btn-primary:hover{background:var(--accent);}
  .btn-orange{background:var(--accent-2);color:#fff;}
  .btn-orange:hover{filter:brightness(1.08);}
  .btn-outline{border:1.4px solid var(--line);color:var(--ink);}
  .btn-outline:hover{border-color:var(--accent);color:var(--accent);}

  .mobile-nav{
    display:none;position:fixed;top:76px;left:0;right:0;bottom:0;background:var(--bg);z-index:90;
    padding:20px 24px;overflow-y:auto;transform:translateY(-8px);opacity:0;pointer-events:none;transition:opacity .25s ease, transform .25s ease;
  }
  .mobile-nav.open{display:block;opacity:1;transform:translateY(0);pointer-events:auto;}
  .mobile-nav a{display:block;padding:14px 0;font-size:16px;font-weight:600;border-bottom:1px solid var(--line);}
  .mobile-nav a.active{color:var(--accent);}

  /* ============ reveal ============ */
  .reveal{opacity:0;transform:translateY(22px);transition:opacity .7s ease, transform .7s ease;}
  .reveal.in{opacity:1;transform:translateY(0);}

  /* ============ DEVICE HERO ============ */
  .device-hero{padding:96px 0 64px;position:relative;z-index:1;}
  .device-hero-inner{display:grid;grid-template-columns:1.05fr .95fr;gap:60px;align-items:center;}
  .eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:12.5px;font-weight:700;letter-spacing:2px;color:var(--accent);text-transform:uppercase;margin-bottom:22px;}
  .eyebrow::before{content:"";width:22px;height:2px;background:var(--accent-2);}
  h1.hero-h{font-size:clamp(34px,4.6vw,52px);font-weight:800;line-height:1.28;letter-spacing:-.5px;}
  .hero-sub{margin-top:22px;font-size:16.5px;line-height:1.85;color:var(--ink-dim);max-width:520px;}
  .hero-actions{margin-top:34px;display:flex;gap:14px;flex-wrap:wrap;}
  .hero-stats{display:grid;grid-template-columns:1fr 1fr;gap:12px;}
  .hs-card{background:var(--bg-alt);border:1px solid var(--line);border-radius:14px;padding:22px 24px;}
  .hs-card b{display:block;font-size:30px;font-weight:800;font-family:"Manrope","Noto Sans SC",sans-serif;color:var(--ink);line-height:1.15;}
  .hs-card b em{font-style:normal;color:var(--accent);}
  .hs-card span{font-size:12.5px;color:var(--ink-dim);margin-top:6px;display:block;}

  /* ============ DEVICE GRID ============ */
  .device-sec{padding:40px 0 110px;position:relative;z-index:1;}
  .filter-bar{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:44px;}
  .filter-btn{padding:10px 20px;border-radius:24px;border:1.4px solid var(--line);font-size:13.5px;font-weight:600;cursor:pointer;color:var(--ink-dim);background:var(--surface);transition:all .2s;}
  .filter-btn:hover{border-color:var(--accent);color:var(--accent);}
  .filter-btn.active{background:var(--panel-dark);border-color:var(--panel-dark);color:#fff;}
  .device-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px;}
  .dev-card{
    border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--surface);
    transition:transform .25s ease, box-shadow .25s ease, border-color .25s ease, opacity .3s ease;
    display:flex;flex-direction:column;
  }
  .dev-card:hover{transform:translateY(-4px);box-shadow:0 20px 44px var(--shadow);border-color:var(--accent);}
  .dev-card{cursor:pointer;}
  .dev-card .dev-cta{position:absolute;right:14px;bottom:12px;z-index:2;font-size:11px;font-weight:700;color:#fff;background:rgba(255,107,61,.92);padding:3px 10px;border-radius:20px;opacity:0;transform:translateY(4px);transition:opacity .25s ease, transform .25s ease;letter-spacing:.5px;}
  .dev-card:hover .dev-cta{opacity:1;transform:translateY(0);}
  .dev-card.hide{display:none;}
  .dev-media{position:relative;aspect-ratio:4/3;background:var(--bg-alt);overflow:hidden;}
  .dev-media img{width:100%;height:100%;object-fit:cover;display:block;transition:transform .45s ease;}
  .dev-card:hover .dev-media img{transform:scale(1.06);}
  .dev-media::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,transparent 55%,rgba(11,31,58,.28));}
  .dev-no{
    position:absolute;top:14px;left:14px;z-index:2;font-size:11px;font-weight:800;letter-spacing:1px;
    color:#fff;background:rgba(11,31,58,.55);backdrop-filter:blur(4px);
    padding:4px 10px;border-radius:20px;
  }
  .dev-cat{
    position:absolute;bottom:12px;left:14px;z-index:2;font-size:11px;font-weight:700;
    color:#fff;background:var(--accent);padding:3px 10px;border-radius:20px;letter-spacing:.5px;
  }
  .dev-body{padding:20px 22px 24px;display:flex;flex-direction:column;flex:1;}
  .dev-body h4{font-size:15.5px;font-weight:700;line-height:1.5;margin-bottom:10px;}
  .dev-body p{font-size:13px;color:var(--ink-dim);line-height:1.75;flex:1;}

  .empty-tip{display:none;text-align:center;padding:60px 0;color:var(--ink-dim);font-size:14px;}

  /* ============ CONTACT (always dark) ============ */
  .contact{background:var(--panel-dark);color:#fff;padding:110px 0;position:relative;z-index:1;}
  .contact-inner{display:grid;grid-template-columns:1fr .85fr;gap:70px;align-items:start;}
  .contact h2{font-size:clamp(28px,3.2vw,40px);font-weight:800;line-height:1.35;}
  .contact p{margin-top:18px;color:rgba(255,255,255,.6);font-size:15px;line-height:1.8;max-width:440px;}
  .contact-info{margin-top:40px;display:flex;flex-direction:column;gap:16px;}
  .contact-info div{font-size:14px;color:rgba(255,255,255,.75);}
  .contact-info b{color:#fff;display:inline-block;width:80px;font-size:12px;letter-spacing:1px;}
  .form-panel{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.12);border-radius:14px;padding:36px;}
  .form-row{margin-bottom:18px;}
  .form-row label{display:block;font-size:12.5px;color:rgba(255,255,255,.6);margin-bottom:8px;}
  .form-row input,.form-row textarea{
    width:100%;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.15);
    border-radius:6px;padding:12px 14px;color:#fff;font-size:14px;font-family:inherit;
    transition:border-color .2s;
  }
  .form-row input:focus,.form-row textarea:focus{outline:none;border-color:#5aa8ff;}
  .form-row textarea{resize:none;height:90px;}
  .form-row input::placeholder,.form-row textarea::placeholder{color:rgba(255,255,255,.3);}
  .form-submit{width:100%;justify-content:center;margin-top:6px;}

  /* ============ FOOTER (always dark) ============ */
  footer{background:var(--panel-dark-2);color:rgba(255,255,255,.8);padding:70px 0 30px;position:relative;z-index:1;}
  .foot-top{display:grid;grid-template-columns:1.4fr repeat(4,1fr);gap:40px;padding-bottom:50px;border-bottom:1px solid rgba(255,255,255,.1);}
  .foot-brand .logo{color:#fff;margin-bottom:16px;}
  .foot-logo-img{height:34px;filter:brightness(0) invert(1);}
  .foot-brand p{font-size:13.5px;color:rgba(255,255,255,.5);line-height:1.8;max-width:280px;}
  .foot-col h5{font-size:12.5px;letter-spacing:1px;color:rgba(255,255,255,.45);margin-bottom:18px;font-weight:700;}
  .foot-col a{display:block;font-size:13.5px;color:rgba(255,255,255,.75);margin-bottom:12px;transition:color .2s;}
  .foot-col a:hover{color:#fff;}
  .foot-bottom{padding-top:26px;display:flex;justify-content:space-between;font-size:12.5px;color:rgba(255,255,255,.4);}

  @media (max-width:980px){
    .main-nav{display:none;}
    .menu-toggle{display:flex;}
    .mobile-back{display:flex;}
    .device-hero-inner,.contact-inner{grid-template-columns:1fr;}
    .foot-top{grid-template-columns:repeat(2,1fr);}
    .container{padding:0 22px;}
    .device-grid{grid-template-columns:repeat(2,1fr);}
  }
  @media (max-width:640px){
    .device-grid{grid-template-columns:1fr;}
    .hero-stats{grid-template-columns:1fr;}
  }