/* Shengchang Electronics - Global B2B Website */
:root {
  --primary: #1a56db;
  --primary-dark: #1e429f;
  --primary-light: #3b82f6;
  --accent: #f59e0b;
  --dark: #0f172a;
  --gray-900: #111827;
  --gray-800: #1f2937;
  --gray-700: #374151;
  --gray-600: #4b5563;
  --gray-500: #6b7280;
  --gray-400: #9ca3af;
  --gray-300: #d1d5db;
  --gray-200: #e5e7eb;
  --gray-100: #f3f4f6;
  --gray-50: #f9fafb;
  --white: #ffffff;
  --success: #10b981;
  --radius: 6px;
  --shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.05);
  --shadow: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--gray-800);
  line-height: 1.6;
  background: var(--white);
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; }
.container { max-width: 1152px; margin: 0 auto; padding: 0 24px; }

/* Header */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-200);
  transition: all 0.3s;
}
.header.scrolled { box-shadow: var(--shadow-sm); }
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--dark); }
.logo-icon {
  width: 36px; height: 36px; background: var(--primary); border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center; color: white; font-weight: 800; font-size: 14px;
}
.nav { display: flex; align-items: center; gap: 32px; }
.nav a { color: var(--gray-700); font-size: 14px; font-weight: 500; transition: color 0.2s; }
.nav a:hover, .nav a.active { color: var(--primary); }
.nav-cta {
  background: var(--primary); color: white !important; padding: 8px 20px; border-radius: var(--radius);
  font-weight: 600; transition: all 0.2s;
}
.nav-cta:hover { background: var(--primary-dark); color: white !important; }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--gray-700); }

/* Hero */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 50%, #ede9fe 100%);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(26,86,219,0.1) 0%, transparent 70%);
  border-radius: 50%;
}
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; position: relative; z-index: 1; }
.hero h1 { font-size: 44px; font-weight: 800; color: var(--dark); line-height: 1.2; margin-bottom: 20px; }
.hero h1 span { color: var(--primary); }
.hero p { font-size: 18px; color: var(--gray-600); margin-bottom: 32px; line-height: 1.7; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px;
  border-radius: var(--radius); font-weight: 600; font-size: 15px; cursor: pointer;
  border: none; transition: all 0.2s; text-decoration: none;
}
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); color: white; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: white; }
.hero-stats { display: flex; gap: 40px; margin-top: 40px; }
.stat-item h3 { font-size: 32px; font-weight: 800; color: var(--primary); }
.stat-item p { font-size: 13px; color: var(--gray-500); margin: 0; }
.hero-image {
  background: white; border-radius: 12px; padding: 20px; box-shadow: var(--shadow-lg);
  display: flex; align-items: center; justify-content: center; min-height: 320px;
}
.hero-placeholder {
  width: 100%; height: 280px; background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
  border-radius: 8px; display: flex; align-items: center; justify-content: center;
  font-size: 60px; color: var(--primary-light);
}

/* Sections */
section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-tag {
  display: inline-block; padding: 4px 14px; background: #eff6ff; color: var(--primary);
  border-radius: 20px; font-size: 13px; font-weight: 600; margin-bottom: 12px;
}
.section-title { font-size: 32px; font-weight: 800; color: var(--dark); margin-bottom: 12px; }
.section-desc { font-size: 16px; color: var(--gray-500); max-width: 600px; margin: 0 auto; }

/* Products */
.products { background: var(--gray-50); }
.product-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.product-card {
  background: white; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-sm); border: 1px solid var(--gray-200);
  transition: all 0.3s; cursor: pointer;
}
.product-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.product-image {
  height: 200px; background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
  display: flex; align-items: center; justify-content: center; font-size: 48px;
}
.product-info { padding: 20px; }
.product-name { font-size: 16px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
.product-desc { font-size: 13px; color: var(--gray-500); margin-bottom: 12px; line-height: 1.5; }
.product-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.product-tag {
  padding: 2px 8px; background: var(--gray-100); color: var(--gray-600);
  border-radius: 4px; font-size: 11px;
}

/* Advantages */
.adv-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.adv-card {
  padding: 28px; background: white; border-radius: var(--radius);
  border: 1px solid var(--gray-200); transition: all 0.3s;
}
.adv-card:hover { border-color: var(--primary); box-shadow: var(--shadow-md); }
.adv-icon {
  width: 48px; height: 48px; background: #eff6ff; border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 16px;
}
.adv-title { font-size: 16px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
.adv-desc { font-size: 14px; color: var(--gray-500); line-height: 1.6; }

/* Certifications */
.certs { background: var(--gray-50); }
.cert-grid { display: flex; justify-content: center; gap: 32px; flex-wrap: wrap; }
.cert-item {
  background: white; padding: 24px 40px; border-radius: var(--radius);
  box-shadow: var(--shadow-sm); text-align: center; min-width: 160px;
}
.cert-badge { font-size: 36px; margin-bottom: 8px; }
.cert-name { font-size: 14px; font-weight: 700; color: var(--dark); }

/* Testimonials */
.testimonial-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 24px; }
.testimonial-card {
  padding: 28px; background: white; border-radius: var(--radius);
  border: 1px solid var(--gray-200);
}
.testimonial-text { font-size: 14px; color: var(--gray-600); line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-avatar {
  width: 40px; height: 40px; border-radius: 50%; background: var(--primary);
  display: flex; align-items: center; justify-content: center; color: white; font-weight: 700;
}
.testimonial-name { font-size: 14px; font-weight: 700; color: var(--dark); }
.testimonial-company { font-size: 12px; color: var(--gray-500); }

/* CTA */
.cta-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white; text-align: center;
}
.cta-section h2 { font-size: 32px; font-weight: 800; margin-bottom: 12px; }
.cta-section p { font-size: 16px; opacity: 0.9; margin-bottom: 28px; }
.cta-section .btn-primary { background: white; color: var(--primary); }
.cta-section .btn-primary:hover { background: var(--gray-100); }

/* Footer */
.footer { background: var(--dark); color: var(--gray-300); padding: 60px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand h3 { color: white; font-size: 18px; margin-bottom: 12px; }
.footer-brand p { font-size: 13px; line-height: 1.7; color: var(--gray-400); }
.footer h4 { color: white; font-size: 14px; margin-bottom: 16px; font-weight: 700; }
.footer ul { list-style: none; }
.footer li { margin-bottom: 8px; }
.footer a { color: var(--gray-400); font-size: 13px; transition: color 0.2s; }
.footer a:hover { color: white; }
.footer-contact li { font-size: 13px; color: var(--gray-400); display: flex; gap: 8px; align-items: flex-start; }
.footer-bottom {
  border-top: 1px solid var(--gray-800); padding-top: 24px;
  display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: var(--gray-500);
}

/* WhatsApp Float */
.whatsapp-float {
  position: fixed; bottom: 24px; right: 24px; z-index: 999;
  width: 56px; height: 56px; background: #25D366; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 28px;
  box-shadow: 0 4px 12px rgba(37,211,102,0.4); cursor: pointer;
  animation: pulse 2s infinite; transition: transform 0.2s;
}
.whatsapp-float:hover { transform: scale(1.1); }
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(37,211,102,0.5); }
  70% { box-shadow: 0 0 0 15px rgba(37,211,102,0); }
  100% { box-shadow: 0 0 0 0 rgba(37,211,102,0); }
}

/* Back to top */
.back-top {
  position: fixed; bottom: 90px; right: 24px; z-index: 998;
  width: 44px; height: 44px; background: var(--primary); color: white;
  border-radius: 50%; display: none; align-items: center; justify-content: center;
  font-size: 20px; cursor: pointer; box-shadow: var(--shadow-md); border: none;
}
.back-top.show { display: flex; }

/* Page header (inner pages) */
.page-header {
  padding: 120px 0 60px; background: linear-gradient(135deg, #eff6ff, #dbeafe);
  text-align: center;
}
.page-header h1 { font-size: 36px; font-weight: 800; color: var(--dark); margin-bottom: 8px; }
.page-header p { font-size: 16px; color: var(--gray-600); }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1.5fr; gap: 40px; }
.contact-info-card {
  background: var(--gray-50); padding: 28px; border-radius: var(--radius);
  border: 1px solid var(--gray-200); margin-bottom: 16px;
}
.contact-info-card h4 { font-size: 15px; font-weight: 700; color: var(--dark); margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.contact-info-card p { font-size: 14px; color: var(--gray-600); margin: 0; }
.contact-form { background: white; padding: 32px; border-radius: var(--radius); border: 1px solid var(--gray-200); }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 600; color: var(--gray-700); margin-bottom: 6px; }
.form-group input, .form-group select, .form-group textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--gray-300); border-radius: var(--radius);
  font-size: 14px; transition: border-color 0.2s; font-family: inherit;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(26,86,219,0.1);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* About */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; margin-bottom: 60px; }
.about-image {
  background: linear-gradient(135deg, #f0f9ff, #e0f2fe); border-radius: var(--radius);
  height: 320px; display: flex; align-items: center; justify-content: center; font-size: 64px;
}
.about-content h2 { font-size: 28px; font-weight: 800; color: var(--dark); margin-bottom: 16px; }
.about-content p { font-size: 15px; color: var(--gray-600); line-height: 1.8; margin-bottom: 16px; }
.factory-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin: 40px 0; }
.factory-img {
  height: 160px; background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
  border-radius: var(--radius); display: flex; align-items: center; justify-content: center;
  font-size: 40px; cursor: pointer; transition: transform 0.2s;
}
.factory-img:hover { transform: scale(1.02); }
.process-steps { display: flex; justify-content: space-between; gap: 16px; margin: 40px 0; flex-wrap: wrap; }
.process-step { flex: 1; min-width: 140px; text-align: center; position: relative; }
.process-num {
  width: 40px; height: 40px; background: var(--primary); color: white; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-weight: 700; margin: 0 auto 12px;
}
.process-step h4 { font-size: 14px; font-weight: 700; color: var(--dark); margin-bottom: 4px; }
.process-step p { font-size: 12px; color: var(--gray-500); }

/* Responsive */
@media (max-width: 768px) {
  .nav { display: none; position: absolute; top: 64px; left: 0; right: 0; background: white;
    flex-direction: column; padding: 20px; gap: 16px; border-bottom: 1px solid var(--gray-200); box-shadow: var(--shadow-md); }
  .nav.open { display: flex; }
  .mobile-menu-btn { display: block; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero h1 { font-size: 32px; }
  .hero-stats { gap: 24px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .contact-grid { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  section { padding: 60px 0; }
  .section-title { font-size: 26px; }
}