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

body {
  font-family: "Segoe UI", Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

/* Navigation */
.navbar {
  background-color: white;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.navbar a {
  color: #2c3e50;
  text-decoration: none;
}

.nav-brand {
  color: #2c3e50;
  font-size: 1.5rem;
  font-weight: bold;
  text-decoration: none;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1rem;
}

.nav-links li a {
  color: #2c3e50;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.nav-links li a:hover,
.nav-links li a.active {
  background-color: #2c3e50;
  color: white;
}

/* Main content */
main {
  padding: 2rem;
  max-width: 1500px;
  margin: 0 auto;
  min-height: calc(100vh - 130px);
}

main h1 {
  color: #2c3e50;
  font-size: 2.2rem;
  text-align: center;
  margin: 2rem 0;
  position: relative;
}

/* Products grid */
.product-card {
  background: white;
  border-radius: 12px;
  padding: 1.5rem;
  text-align: left;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  cursor: pointer;
}

.product-card img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  object-fit: cover;
}

.product-card h3 {
  color: #2c3e50;
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0;
  text-align: center;
}

/* Product Brief Description */
.product-brief {
  color: #666;
  font-size: 0.95rem;
  line-height: 1.5;
  text-align: center;
  margin: 0;
}

/* Specifications Styling */
.product-specs {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 1rem;
}

.spec-item {
  display: flex;
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
  line-height: 1.5;
}

.spec-item:last-child {
  margin-bottom: 0;
}

.spec-label {
  font-weight: 600;
  min-width: 100px;
  color: #2c3e50;
}

.spec-value {
  color: #666;
}

/* Usage Instructions Styling */
.product-usage {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.usage-section h4 {
  color: #2c3e50;
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.usage-section p {
  color: #666;
  font-size: 0.95rem;
  margin: 0;
  line-height: 1.5;
}

/* Grid Layout */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  padding: 1rem;
}

/* Contact page styles */
.contact-simple {
  max-width: 600px;
  margin: 2rem auto;
  padding: 2rem;
  background: white;
  border-radius: 16px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.contact-simple h1 {
  color: #2c3e50;
  font-size: 2rem;
  margin-bottom: 2rem;
  text-align: center;
  position: relative;
}

.contact-simple h1:after {
  content: "";
  display: block;
  width: 60px;
  height: 3px;
  background: #2c3e50;
  margin: 1rem auto 0;
}

.company-name h2 {
  color: #2c3e50;
  font-size: 1.8rem;
  text-align: center;
  margin-bottom: 2rem;
}

.zalo-contact {
  background: #f8f9fa;
  padding: 1.5rem;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  transition: background 0.3s ease, transform 0.3s ease;
}

.zalo-contact:hover {
  background: #e9ecef;
  transform: translateY(-3px);
}

.zalo-details {
  text-align: left;
}

.label {
  display: block;
  color: #6c757d;
  font-size: 0.9rem;
  margin-bottom: 0.3rem;
}

.zalo-number {
  color: #0068ff;
  font-size: 1.5rem;
  font-weight: bold;
  text-decoration: none;
  display: block;
  transition: color 0.3s ease;
}

.zalo-number:hover {
  color: #0056b3;
}

/* Footer */
footer {
  background-color: white;
  color: #2c3e50;
  text-align: center;
  padding: 1rem;
  border-top: 1px solid #eee;
}

/* Responsive design */
@media (max-width: 768px) {
  .navbar {
    padding: 1rem;
  }

  .products-grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
  }

  .contact-simple {
    margin: 1rem;
    padding: 1.5rem;
  }

  .company-name h2 {
    font-size: 1.5rem;
  }

  .zalo-number {
    font-size: 1.3rem;
  }

  .product-card {
    padding: 1rem;
  }

  .spec-item {
    font-size: 0.9rem;
  }

  .spec-label {
    min-width: 90px;
  }

  .product-usage {
    gap: 0.8rem;
  }
}

@media (max-width: 480px) {
  .navbar {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-links {
    width: 100%;
    justify-content: center;
  }

  .contact-simple {
    padding: 1rem;
  }

  .zalo-contact {
    padding: 1rem;
  }
}