/* ===== HongTu Tech — Product Hub ===== */
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --bg:#06080f;--bg2:#0c1019;--bg3:#131825;--bg4:#1a2035;
  --border:#1e2538;--border2:#2a3350;
  --text:#e5e7eb;--muted:#9ca3af;--dim:#6b7280;
  --blue:#3b82f6;--red:#dc2626;
  --font:'Inter',-apple-system,BlinkMacSystemFont,sans-serif;
}
html{scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
.container{max-width:1100px;margin:0 auto;padding:0 24px}

/* ===== Nav ===== */
.nav{position:fixed;top:0;left:0;width:100%;z-index:100;padding:16px 0;transition:all .3s}
.nav.scrolled{background:rgba(6,8,15,0.92);backdrop-filter:blur(16px);border-bottom:1px solid var(--border);padding:10px 0}
.nav-inner{display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:20px}
.brand img{height:32px;width:auto;border-radius:8px}
.brand-text{color:var(--text)}
.nav-links{display:flex;gap:28px}
.nav-links a{font-size:14px;font-weight:500;color:var(--muted);transition:color .3s;position:relative}
.nav-links a:hover,.nav-links a.active{color:var(--text)}
.nav-links a::after{content:'';position:absolute;bottom:-4px;left:0;width:0;height:2px;background:var(--blue);transition:width .3s}
.nav-links a:hover::after,.nav-links a.active::after{width:100%}
.nav-right{display:flex;align-items:center;gap:12px}
.lang-toggle{background:var(--bg3);border:1px solid var(--border);color:var(--muted);padding:6px 12px;border-radius:6px;cursor:pointer;font-size:12px;font-weight:600;transition:all .3s;font-family:var(--font)}
.lang-toggle:hover{border-color:var(--blue);color:var(--text)}
.nav-cta{background:var(--blue);color:#fff;padding:8px 20px;border-radius:8px;font-weight:600;font-size:14px;transition:all .3s}
.nav-cta:hover{background:#2563eb;transform:translateY(-1px);box-shadow:0 4px 16px rgba(59,130,246,0.3)}

/* ===== Hero ===== */
.hub-hero{padding:140px 0 80px;text-align:center;position:relative;overflow:hidden}
.hub-grid-bg{position:absolute;inset:0;background-image:radial-gradient(rgba(255,255,255,0.025) 1px,transparent 1px);background-size:40px 40px;z-index:0}
.hub-glow{position:absolute;width:500px;height:500px;border-radius:50%;z-index:0;filter:blur(80px);opacity:.25}
.hub-glow.g1{top:-200px;left:-100px;background:var(--blue)}
.hub-glow.g2{bottom:-200px;right:-100px;background:var(--red)}
.hub-hero-inner{position:relative;z-index:1}
.hub-brand{margin-bottom:24px}
.hub-logo{width:72px;height:72px;border-radius:16px;margin-bottom:16px}
.hub-hero h1{font-size:52px;font-weight:900;letter-spacing:-2px;margin-bottom:8px}
.hub-tagline{font-size:18px;color:var(--muted);font-weight:500;letter-spacing:1px}
.hub-desc{font-size:17px;color:var(--dim);max-width:600px;margin:0 auto;line-height:1.8}

/* Quick Nav Buttons in Hero */
.hub-quick-nav{display:flex;justify-content:center;gap:16px;margin-top:36px;flex-wrap:wrap}
.qn-btn{display:inline-flex;align-items:center;gap:10px;padding:14px 28px;border-radius:12px;background:var(--bg3);border:1px solid var(--border);font-size:16px;font-weight:600;color:var(--text);transition:all .35s;text-decoration:none}
.qn-btn:hover{transform:translateY(-3px);border-color:var(--border2);box-shadow:0 12px 36px rgba(0,0,0,0.4);background:var(--bg4)}
.qn-btn svg{width:18px;height:18px;opacity:.4;transition:all .3s}
.qn-btn:hover svg{opacity:1;transform:translateX(4px)}
.qn-dot{width:10px;height:10px;border-radius:50%;flex-shrink:0;box-shadow:0 0 8px currentColor}

/* ===== Section Common ===== */
.hub-sec-header{text-align:center;margin-bottom:48px}
.hub-label{display:inline-block;font-size:11px;font-weight:700;letter-spacing:2px;color:var(--blue);text-transform:uppercase;margin-bottom:12px}
.hub-sec-header h2{font-size:32px;font-weight:800;letter-spacing:-.5px}

/* ===== Product Grid ===== */
.hub-products{padding:80px 0}
.product-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:24px}
.product-card{display:flex;flex-direction:column;background:var(--bg3);border:1px solid var(--border);border-radius:16px;padding:32px;transition:all .4s cubic-bezier(.25,.46,.45,.94);position:relative;overflow:hidden;text-decoration:none}
.product-card::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;transform:scaleX(0);transition:transform .4s;transform-origin:left}
.product-card:hover::before{transform:scaleX(1)}
.product-card:hover{transform:translateY(-8px);border-color:var(--border2);box-shadow:0 20px 60px rgba(0,0,0,0.4)}
.pc-header{display:flex;align-items:center;gap:16px;margin-bottom:16px}
.pc-icon{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.pc-icon svg{width:24px;height:24px;color:#fff}
.pc-header strong{font-size:22px;font-weight:700}
.product-card p{font-size:14px;color:var(--muted);line-height:1.7;flex:1;margin-bottom:20px}
.pc-explore{font-size:13px;font-weight:600;color:var(--dim);display:flex;align-items:center;gap:6px;transition:color .3s}
.pc-explore svg{width:16px;height:16px;transition:transform .3s}
.product-card:hover .pc-explore{color:var(--text)}
.product-card:hover .pc-explore svg{transform:translateX(4px)}

/* Dynamic card border-top color */
.product-card:nth-child(1)::before{background:var(--blue)}
.product-card:nth-child(2)::before{background:var(--red)}
.product-card:nth-child(3)::before{background:#10b981}
.product-card:nth-child(4)::before{background:#8b5cf6}
.product-card:nth-child(5)::before{background:#f59e0b}
.product-card:nth-child(6)::before{background:#06b6d4}

/* ===== About ===== */
.hub-about{padding:80px 0;background:var(--bg2);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.about-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.about-card{background:var(--bg3);border:1px solid var(--border);border-radius:14px;padding:28px;text-align:center;transition:all .35s}
.about-card:hover{transform:translateY(-4px);border-color:var(--border2);box-shadow:0 12px 32px rgba(0,0,0,0.3)}
.ac-icon{width:44px;height:44px;color:var(--blue);margin:0 auto 14px}
.ac-icon svg{width:100%;height:100%}
.about-card strong{display:block;font-size:15px;margin-bottom:8px}
.about-card p{font-size:13px;color:var(--muted);line-height:1.6}

/* ===== CTA ===== */
.hub-cta{padding:100px 0;text-align:center;position:relative;overflow:hidden}
.hub-cta::before{content:'';position:absolute;top:50%;left:50%;width:600px;height:600px;background:radial-gradient(circle,rgba(59,130,246,0.1) 0%,transparent 70%);transform:translate(-50%,-50%);border-radius:50%}
.hub-cta-inner{position:relative;z-index:1}
.hub-cta h2{font-size:34px;font-weight:800;margin-bottom:14px}
.hub-cta p{font-size:16px;color:var(--muted);max-width:480px;margin:0 auto 32px}
.hub-cta-btns{display:flex;gap:16px;justify-content:center}
.btn-primary{background:var(--blue);color:#fff;padding:14px 32px;border-radius:10px;font-weight:600;font-size:15px;transition:all .3s;display:inline-block}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(59,130,246,0.3)}
.btn-ghost{border:1px solid var(--border2);color:var(--text);padding:14px 32px;border-radius:10px;font-weight:600;font-size:15px;transition:all .3s;display:inline-block}
.btn-ghost:hover{border-color:var(--muted);background:var(--bg3)}

/* ===== Footer ===== */
.hub-footer{padding:32px 0;border-top:1px solid var(--border)}
.hub-footer-row{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px}
.hf-brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:14px}
.hf-brand img{height:24px;border-radius:6px}
.hf-links{display:flex;gap:20px}
.hf-links a{font-size:13px;color:var(--dim);transition:color .3s}
.hf-links a:hover{color:var(--text)}
.hub-footer p{font-size:12px;color:var(--dim)}

/* ===== Lang Toggle ===== */
.hub-lang{position:fixed;top:20px;right:20px;z-index:100;background:var(--bg3);border:1px solid var(--border);color:var(--muted);padding:8px 14px;border-radius:8px;cursor:pointer;font-size:12px;font-weight:700;letter-spacing:.5px;font-family:var(--font);transition:all .3s}
.hub-lang:hover{border-color:var(--blue);color:var(--text)}

/* ===== Animations ===== */
.fade-in{opacity:0;transform:translateY(24px);transition:opacity .6s,transform .6s}
.fade-in.show{opacity:1;transform:none}

/* ===== Responsive ===== */
@media(max-width:900px){
  .hub-hero{padding:100px 0 60px}
  .hub-hero h1{font-size:38px}
  .about-grid{grid-template-columns:repeat(2,1fr)}
  .product-grid{grid-template-columns:1fr}
  .qn-btn{padding:10px 20px;font-size:14px}
  .hub-quick-nav{gap:10px}
}
@media(max-width:600px){
  .nav-links{display:none}
  .nav-cta{display:none}
  .brand{font-size:16px}
  .brand img{height:26px}
  .about-grid{grid-template-columns:1fr}
  .hub-footer-row{flex-direction:column;text-align:center}
  .hf-links{justify-content:center;flex-wrap:wrap}
  .hub-hero h1{font-size:30px}
  .hub-tagline{font-size:15px}
  .hub-desc{font-size:14px}
  .hub-quick-nav{flex-direction:column;align-items:center}
  .qn-btn{width:100%;max-width:280px;justify-content:center;padding:12px 20px;font-size:14px}
  .container{padding:0 16px}
  .hub-cta h2{font-size:24px}
  .hub-cta p{font-size:14px}
  .hub-cta-btns{flex-direction:column;align-items:center;gap:10px}
  .btn-primary,.btn-ghost{width:80%;text-align:center}
  .hub-sec-header h2{font-size:26px}
  .hub-products{padding:60px 0}
  .hub-about{padding:60px 0}
  .hub-cta{padding:60px 0}
  .hub-lang{top:12px;right:12px;padding:6px 10px;font-size:11px}
}