/* Shandong Longhai Lubricating Technology - Main Stylesheet */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --primary: #1a56db;
  --primary-dark: #1e429f;
  --accent: #f59e0b;
  --dark: #1f2937;
  --gray: #6b7280;
  --light: #f3f4f6;
  --white: #ffffff;
}
body { font-family: 'Segoe UI', Arial, sans-serif; color: var(--dark); line-height: 1.6; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; height: auto; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* Header */
header { background: var(--white); box-shadow: 0 2px 10px rgba(0,0,0,0.1); position: sticky; top: 0; z-index: 1000; }
.header-inner { display: flex; justify-content: space-between; align-items: center; padding: 15px 0; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-text { font-size: 24px; font-weight: bold; color: var(--primary); }
.logo-sub { font-size: 12px; color: var(--gray); }
nav ul { display: flex; list-style: none; gap: 30px; }
nav a { font-weight: 500; transition: color 0.3s; }
nav a:hover { color: var(--primary); }
.lang-selector select { padding: 6px 12px; border: 1px solid #ddd; border-radius: 4px; cursor: pointer; }

/* Hero */
.hero { position: relative; height: 500px; display: flex; align-items: center; color: var(--white); overflow: hidden; }
.hero-bg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; object-fit: cover; }
.hero-overlay { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: linear-gradient(135deg, rgba(26,86,219,0.85), rgba(30,66,159,0.7)); }
.hero-content { position: relative; z-index: 1; max-width: 700px; }
.hero h1 { font-size: 48px; margin-bottom: 20px; line-height: 1.2; }
.hero p { font-size: 20px; margin-bottom: 30px; opacity: 0.95; }
.btn { display: inline-block; padding: 14px 32px; border-radius: 6px; font-weight: 600; transition: all 0.3s; cursor: pointer; border: none; font-size: 16px; }
.btn-primary { background: var(--accent); color: var(--dark); }
.btn-primary:hover { background: #d97706; transform: translateY(-2px); }
.btn-outline { background: transparent; color: var(--white); border: 2px solid var(--white); }
.btn-outline:hover { background: var(--white); color: var(--primary); }

/* Sections */
section { padding: 80px 0; }
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 36px; color: var(--dark); margin-bottom: 15px; }
.section-title p { color: var(--gray); font-size: 18px; max-width: 600px; margin: 0 auto; }

/* Features */
.features { background: var(--light); }
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; }
.feature-card { background: var(--white); padding: 30px; border-radius: 10px; text-align: center; box-shadow: 0 4px 15px rgba(0,0,0,0.05); transition: transform 0.3s; }
.feature-card:hover { transform: translateY(-5px); }
.feature-icon { font-size: 48px; margin-bottom: 20px; }
.feature-card h3 { font-size: 20px; margin-bottom: 10px; color: var(--primary); }
.feature-card p { color: var(--gray); font-size: 14px; }

/* Products */
.products-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 25px; }
.product-card { background: var(--white); border: 1px solid #e5e7eb; border-radius: 10px; overflow: hidden; transition: all 0.3s; }
.product-card:hover { box-shadow: 0 8px 25px rgba(0,0,0,0.1); transform: translateY(-3px); }
.product-img { height: 200px; display: flex; align-items: center; justify-content: center; background: var(--light); padding: 20px; }
.product-img img { max-height: 160px; object-fit: contain; }
.product-info { padding: 20px; }
.product-info h3 { font-size: 18px; margin-bottom: 8px; color: var(--dark); }
.product-info p { color: var(--gray); font-size: 14px; margin-bottom: 15px; }
.product-tag { display: inline-block; padding: 4px 12px; background: #dbeafe; color: var(--primary); border-radius: 20px; font-size: 12px; font-weight: 500; }

/* About preview */
.about-preview { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.about-img img { border-radius: 10px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }
.about-text h2 { font-size: 32px; margin-bottom: 20px; color: var(--dark); }
.about-text p { color: var(--gray); margin-bottom: 15px; line-height: 1.8; }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 30px; }
.stat-item { text-align: center; }
.stat-number { font-size: 36px; font-weight: bold; color: var(--primary); }
.stat-label { font-size: 14px; color: var(--gray); }

/* CTA */
.cta { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: var(--white); text-align: center; }
.cta h2 { font-size: 36px; margin-bottom: 20px; }
.cta p { font-size: 18px; margin-bottom: 30px; opacity: 0.9; }

/* Footer */
footer { background: var(--dark); color: #9ca3af; padding: 60px 0 20px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-col h4 { color: var(--white); margin-bottom: 20px; font-size: 18px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a:hover { color: var(--white); }
.footer-bottom { border-top: 1px solid #374151; padding-top: 20px; text-align: center; font-size: 14px; }

/* Page header */
.page-header { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: var(--white); padding: 60px 0; text-align: center; }
.page-header h1 { font-size: 40px; margin-bottom: 10px; }
.page-header p { opacity: 0.9; font-size: 18px; }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; }
.contact-info h3 { font-size: 24px; margin-bottom: 20px; }
.contact-item { display: flex; gap: 15px; margin-bottom: 25px; align-items: flex-start; }
.contact-icon { font-size: 24px; min-width: 40px; }
.contact-item h4 { margin-bottom: 5px; color: var(--primary); }
.contact-item p { color: var(--gray); }
.contact-form { background: var(--light); padding: 30px; border-radius: 10px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 500; }
.form-group input, .form-group textarea, .form-group select { width: 100%; padding: 12px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px; }
.form-group textarea { min-height: 120px; resize: vertical; }

/* Responsive */
@media (max-width: 768px) {
  .features-grid, .products-grid { grid-template-columns: repeat(2, 1fr); }
  .about-preview, .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 32px; }
  nav ul { display: none; }
}