:root {
  --primary: #1a5f7a;
  --primary-light: #2d8fb0;
  --secondary: #57c5b6;
  --accent: #159895;
  --bg-light: #f8fffe;
  --bg-white: #ffffff;
  --text-dark: #1a2e35;
  --text-body: #4a5c5f;
  --text-light: #7a8f92;
  --border: #e0f2f1;
  --shadow: rgba(21, 152, 149, 0.08);
  --shadow-hover: rgba(21, 152, 149, 0.15);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg-light);
  color: var(--text-body);
  line-height: 1.7;
  font-size: 16px;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  padding: 0 48px;
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 40px;
}

.nav a {
  color: var(--text-body);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: var(--transition);
}

.nav a:hover {
  color: var(--primary);
}

.nav a:hover::after {
  width: 100%;
}

.lang-btn {
  background: none;
  border: 1.5px solid var(--secondary);
  color: var(--accent);
  padding: 6px 16px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
}

.lang-btn:hover {
  background: var(--secondary);
  color: var(--bg-white);
}

/* Hero */
.hero {
  padding: 160px 48px 100px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-white) 0%, var(--bg-light) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(87, 197, 182, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(26, 95, 122, 0.06) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 2px;
  margin-bottom: 16px;
}

.hero h2 {
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--accent);
  margin-bottom: 24px;
  font-style: italic;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-light);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* Sections */
.section {
  padding: 100px 48px;
  max-width: 1280px;
  margin: 0 auto;
}

.section-title {
  text-align: center;
  margin-bottom: 64px;
}

.section-title h2 {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--secondary);
  margin: 16px auto 0;
  border-radius: 2px;
}

/* About */
.about {
  background: var(--bg-white);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text p {
  margin-bottom: 20px;
  color: var(--text-body);
  font-size: 1.05rem;
}

.about-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.about-visual .stat {
  background: var(--bg-light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
}

.about-visual .stat-number {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--secondary);
  display: block;
}

.about-visual .stat-label {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-top: 4px;
}

/* Products */
.products {
  background: var(--bg-light);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 28px;
}

.product-card {
  background: var(--bg-white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 2px 12px var(--shadow);
  transition: var(--transition);
  cursor: pointer;
}

.product-card:hover {
  box-shadow: 0 8px 30px var(--shadow-hover);
}

.product-image-wrapper {
  position: relative;
  width: 100%;
  padding-top: 75%;
  overflow: hidden;
  background: var(--bg-light);
}

.product-image-wrapper img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.product-card:hover .product-image-wrapper img {
  transform: scale(1.05);
}

/* Decorative corner overlay */
.product-image-wrapper::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 0;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, transparent 50%, var(--secondary) 50%);
  opacity: 0.7;
  transition: var(--transition);
}

.product-image-wrapper::before {
  content: '';
  position: absolute;
  bottom: 8px;
  right: 8px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--primary);
  opacity: 0.5;
  z-index: 1;
}

.product-card:hover .product-image-wrapper::after {
  width: 80px;
  height: 80px;
  opacity: 0.9;
}

.product-card:hover .product-image-wrapper::before {
  opacity: 0.8;
  transform: scale(1.2);
}

.product-info {
  padding: 20px;
  text-align: center;
}

.product-info h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-dark);
}

/* Services */
.services {
  background: var(--bg-white);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 28px;
}

.service-card {
  background: var(--bg-light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
  transition: var(--transition);
}

.service-card:hover {
  border-color: var(--secondary);
  box-shadow: 0 4px 20px var(--shadow);
  transform: translateY(-4px);
}

.service-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--secondary), var(--accent));
  border-radius: 50%;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.service-icon svg {
  width: 28px;
  height: 28px;
  fill: var(--bg-white);
}

.service-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 12px;
}

.service-card p {
  font-size: 0.95rem;
  color: var(--text-light);
  line-height: 1.7;
}

/* Footer */
.footer {
  background: var(--primary);
  color: rgba(255, 255, 255, 0.7);
  text-align: center;
  padding: 40px 48px;
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .header {
    padding: 0 24px;
  }

  .header-inner {
    height: 64px;
  }

  .nav {
    gap: 20px;
  }

  .hero {
    padding: 120px 24px 80px;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .hero h2 {
    font-size: 1.1rem;
  }

  .section {
    padding: 60px 24px;
  }

  .about-content {
    grid-template-columns: 1fr;
  }

  .about-visual {
    grid-template-columns: 1fr 1fr;
  }

  .products-grid,
  .services-grid {
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  }
}