/* =============================================
   yoyang TECH - Light Industrial Theme
   Plan A: Professional B2B Style
   ============================================= */

:root {
  --primary: #1E4D8C;
  --primary-dark: #163A6B;
  --accent: #00A67E;
  --bg: #FFFFFF;
  --bg-alt: #F4F6F9;
  --card: #FFFFFF;
  --text: #1A2B3C;
  --text-2: #5A6B7B;
  --text-muted: #8A9BAC;
  --border: #E3E8EF;
  --shadow: 0 2px 12px rgba(26,43,60,0.06);
  --shadow-md: 0 4px 20px rgba(26,43,60,0.1);
}

* { 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;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

/* Navigation */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(12px);
  padding: 0 40px;
  display: flex; justify-content: space-between; align-items: center;
  height: 68px;
  border-bottom: 1px solid var(--border);
}
.nav-logo { font-size: 1.25rem; font-weight: 700; letter-spacing: 0.5px; }
.nav-logo span { color: var(--primary); }
.nav-links { display: flex; align-items: center; gap: 2rem; list-style: none; }
.nav-links a {
  color: var(--text-2); font-size: 0.9rem; font-weight: 500;
  transition: color 0.3s; text-decoration: none;
}
.nav-links a:hover { color: var(--primary); }
.nav-cta {
  padding: 8px 20px !important;
  background: var(--primary) !important;
  color: #fff !important;
  border-radius: 6px;
  transition: background 0.3s !important;
}
.nav-cta:hover { background: var(--primary-dark) !important; text-decoration: none !important; }

/* Buttons */
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; background: var(--primary); color: #fff;
  border-radius: 8px; font-weight: 600; font-size: 0.95rem;
  transition: all 0.3s; text-decoration: none; cursor: pointer;
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); text-decoration: none; }
.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; background: transparent; color: var(--text);
  border: 1.5px solid var(--border); border-radius: 8px;
  font-weight: 600; font-size: 0.95rem;
  transition: all 0.3s; text-decoration: none;
}
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); text-decoration: none; }

/* Section base */
.section { padding: 80px 40px; max-width: 1200px; margin: 0 auto; }
.section-alt { background: var(--bg-alt); border-radius: 16px; margin: 40px auto; }
.section-alt .section { padding: 60px 40px; }
.section-header { text-align: center; max-width: 640px; margin: 0 auto 50px; }
.section-tag {
  display: inline-block; padding: 5px 14px;
  background: rgba(30,77,140,0.08); border: 1px solid rgba(30,77,140,0.15);
  border-radius: 4px;
  color: var(--primary); font-size: 0.72rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 1px;
  margin-bottom: 14px;
}
.section-header h2 { font-size: 2rem; font-weight: 700; margin-bottom: 14px; color: var(--text); }
.section-subtitle { color: var(--text-2); font-size: 1rem; }

/* Hero */
.hero {
  position: relative; padding-top: 68px;
  min-height: 92vh; display: flex; align-items: center;
  background: linear-gradient(155deg, #1E4D8C 0%, #163A6B 100%);
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; z-index: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: 0.12; }
.hero-overlay { position: absolute; inset: 0; background: linear-gradient(135deg, rgba(22,58,107,0.85) 0%, rgba(30,77,140,0.7) 100%); z-index: 1; }
.hero-content {
  position: relative; z-index: 2;
  max-width: 1200px; margin: 0 auto; padding: 60px 40px;
  width: 100%;
}
.hero-badge {
  display: inline-block; padding: 6px 16px;
  background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.25);
  border-radius: 20px; color: rgba(255,255,255,0.95); font-size: 0.78rem; font-weight: 600;
  margin-bottom: 24px;
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem); font-weight: 800; line-height: 1.15;
  color: #fff; margin-bottom: 20px;
}
.hero h1 span { color: #5CA8E0; }
.hero p { font-size: 1.1rem; color: rgba(255,255,255,0.85); max-width: 560px; line-height: 1.7; margin-bottom: 36px; }
.hero-buttons { display: flex; gap: 14px; flex-wrap: wrap; }

/* About */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 5rem; align-items: center; }
.about-image { border-radius: 12px; overflow: hidden; box-shadow: var(--shadow-md); }
.about-image img { width: 100%; height: 420px; object-fit: cover; }
.about-content h3 { font-size: 1.6rem; font-weight: 700; margin-bottom: 1.2rem; }
.about-content p { color: var(--text-2); margin-bottom: 1rem; line-height: 1.8; font-size: 0.98rem; }
.about-stats { display: grid; grid-template-columns: repeat(3,1fr); gap: 1.2rem; margin-top: 2rem; }
.stat-item {
  text-align: center; padding: 1.2rem 1rem;
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: 10px;
}
.stat-number { font-size: 1.8rem; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 0.82rem; color: var(--text-2); margin-top: 4px; }

/* Products */
.products-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px,1fr)); gap: 1.5rem; }
.product-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 12px; overflow: hidden;
  transition: all 0.35s; box-shadow: var(--shadow);
}
.product-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: rgba(30,77,140,0.2); }
.product-card-image { height: 220px; overflow: hidden; }
.product-card-image img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.product-card:hover .product-card-image img { transform: scale(1.04); }
.product-card-body { padding: 1.4rem; }
.product-card-category { font-size: 0.7rem; color: var(--accent); font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 6px; }
.product-card h3 { font-size: 1.05rem; margin-bottom: 8px; }
.product-card p { color: var(--text-2); font-size: 0.88rem; line-height: 1.65; margin-bottom: 14px; }
.tag {
  display: inline-block; padding: 3px 10px;
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: 4px;
  font-size: 0.72rem; color: var(--text-2); font-weight: 500;
}

/* Features */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); gap: 1.5rem; }
.feature-card {
  padding: 2rem 1.5rem; background: var(--card);
  border: 1px solid var(--border); border-radius: 12px;
  transition: all 0.3s; box-shadow: var(--shadow);
}
.feature-card:hover { border-color: rgba(30,77,140,0.25); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.feature-icon {
  width: 54px; height: 54px; margin-bottom: 1.2rem;
  background: rgba(30,77,140,0.08); border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
}
.feature-icon svg { width: 26px; height: 26px; stroke: var(--primary); fill: none; stroke-width: 2; }
.feature-card h3 { font-size: 1.05rem; margin-bottom: 8px; }
.feature-card p { color: var(--text-2); font-size: 0.88rem; line-height: 1.7; }

/* Cert */
.cert-bar { display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 2rem; justify-content: center; }
.cert-item {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 18px; background: var(--card);
  border: 1px solid var(--border); border-radius: 8px;
  font-size: 0.88rem; font-weight: 600; color: var(--text);
}
.cert-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); flex-shrink: 0; }

/* FAQ */
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 10px; }
.faq-item { background: var(--card); border: 1px solid var(--border); border-radius: 10px; overflow: hidden; transition: border-color 0.3s; }
.faq-item:hover { border-color: rgba(30,77,140,0.2); }
.faq-question {
  padding: 1.1rem 1.4rem; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
  font-weight: 600; font-size: 0.95rem; user-select: none;
}
.faq-question .icon { font-size: 1.3rem; color: var(--text-muted); transition: all 0.3s; flex-shrink: 0; font-style: normal; }
.faq-item.active .faq-question .icon { transform: rotate(45deg); color: var(--primary); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.4s ease; padding: 0 1.4rem; color: var(--text-2); font-size: 0.9rem; line-height: 1.7; }
.faq-item.active .faq-answer { max-height: 300px; padding: 0 1.4rem 1.2rem; }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; }
.contact-info h3 { font-size: 1.3rem; font-weight: 700; margin-bottom: 1.4rem; }
.contact-details { display: flex; flex-direction: column; gap: 1.2rem; }
.contact-row {
  display: flex; align-items: flex-start; gap: 1rem;
  padding: 14px 16px; background: var(--bg-alt);
  border: 1px solid var(--border); border-radius: 10px;
}
.contact-icon {
  width: 42px; height: 42px; flex-shrink: 0;
  background: rgba(30,77,140,0.08); border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: var(--primary); font-size: 1.2rem;
}
.contact-text h4 { font-size: 0.78rem; color: var(--text-2); font-weight: 500; margin-bottom: 3px; }
.contact-text p, .contact-text a { font-size: 0.98rem; font-weight: 500; color: var(--primary); }
.contact-form {
  background: var(--card); padding: 2.2rem; border-radius: 12px;
  border: 1px solid var(--border); box-shadow: var(--shadow);
}
.contact-form h3 { font-size: 1.1rem; margin-bottom: 1.4rem; }
.form-group { margin-bottom: 1.1rem; }
.form-group label { display: block; font-size: 0.82rem; color: var(--text-2); margin-bottom: 5px; font-weight: 500; }
.form-group input, .form-group textarea, .form-group select {
  width: 100%; padding: 10px 12px;
  background: var(--bg); border: 1px solid var(--border); border-radius: 8px;
  color: var(--text); font-size: 0.92rem; font-family: inherit; transition: border-color 0.3s;
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus { outline: none; border-color: var(--primary); }
.form-group textarea { height: 110px; resize: vertical; }

/* Footer */
.footer {
  background: #163A6B; color: #fff;
  border-top: 1px solid var(--border); padding: 3.5rem 2rem 1.5rem;
}
.footer-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 2.5rem; margin-bottom: 2.5rem; }
.footer-brand h3 { font-size: 1.2rem; margin-bottom: 1rem; }
.footer-brand h3 span { color: #5CA8E0; }
.footer-brand p { color: rgba(255,255,255,0.7); font-size: 0.85rem; line-height: 1.7; max-width: 280px; }
.footer-col h4 { font-size: 0.85rem; margin-bottom: 1.1rem; color: #fff; font-weight: 600; }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 0.6rem; }
.footer-col ul a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.85rem; transition: color 0.3s; }
.footer-col ul a:hover { color: #fff; }
.footer-bottom { max-width: 1200px; margin: 0 auto; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,0.12); display: flex; justify-content: space-between; align-items: center; font-size: 0.78rem; color: rgba(255,255,255,0.55); }

/* Scroll reveal */
.reveal { opacity: 0; transform: translateY(25px); transition: all 0.6s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* WhatsApp float */
.whatsapp-float {
  position: fixed; bottom: 24px; right: 24px; z-index: 999;
  width: 54px; height: 54px; background: #25D366; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 1.6rem; text-decoration: none;
  box-shadow: 0 4px 15px rgba(37,211,102,0.4);
  transition: all 0.3s;
}
.whatsapp-float:hover { transform: scale(1.1); box-shadow: 0 6px 20px rgba(37,211,102,0.5); text-decoration: none; }

/* Mobile toggle */
.mobile-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
.mobile-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: all 0.3s; }

/* Responsive */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .contact-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav { padding: 0 20px; }
  .nav-links { display: none; }
  .mobile-toggle { display: flex; }
  .section { padding: 50px 20px; }
  .section-alt { border-radius: 0; margin: 0; }
  .section-alt .section { padding: 50px 20px; }
  .hero { min-height: 85vh; }
  .hero-content { padding: 50px 20px; }
  .hero h1 { font-size: 1.9rem; }
  .hero-buttons { flex-direction: column; align-items: flex-start; }
  .about-stats { grid-template-columns: repeat(3,1fr); gap: 0.8rem; }
  .products-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
}
@media (max-width: 480px) {
  .about-stats { grid-template-columns: 1fr 1fr 1fr; gap: 0.6rem; }
  .stat-item { padding: 1rem 0.5rem; }
  .stat-number { font-size: 1.5rem; }
}