:root {
  --primary-blue: #1E2F97;
  --primary-purple: #6A5ACD;
  --accent-orange: #FF9800;
  --accent-green: #34C759;
  --background-white: #FFFFFF;
  --background-gray: #F0F0F0;
  --font-family: 'Roboto', sans-serif;
}

body {
  margin: 0;
  font-family: var(--font-family);
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  color: #333;
  line-height: 1.6;
}

.header {
  background: linear-gradient(90deg, var(--primary-blue), var(--primary-purple));
  color: white;
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover;
  opacity: 0.1;
  z-index: 0;
}

.header-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.note {
  background-color: rgba(255, 255, 255, 0.2);
  padding: 0.5rem 1rem;
  border-radius: 20px;
  display: inline-block;
  margin-bottom: 1rem;
  font-size: 0.9rem;
  backdrop-filter: blur(5px);
}

.main-container {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 2rem;
}

.article-container {
  background-color: white;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  padding: 2rem;
  margin-bottom: 2rem;
}

.tab-container {
  display: flex;
  background-color: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  margin: 2rem 0;
}

.tab {
  flex: 1;
  padding: 1rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
}

.tab:hover {
  background-color: var(--background-gray);
}

.tab.active {
  color: var(--primary-purple);
}

.tab.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-green));
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.grid-item {
  background-color: white;
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.grid-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.image-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.decorative-image {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease;
}

.decorative-image img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.5s ease;
}

.decorative-image:hover {
  transform: scale(1.02);
}

.decorative-image:hover img {
  transform: scale(1.1);
}

pre {
  background: linear-gradient(45deg, #f8f9fa, #e9ecef);
  border-left: 4px solid var(--primary-blue);
  border-radius: 0 8px 8px 0;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  margin: 2rem 0;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  border-radius: 8px;
  overflow: hidden;
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

th {
  background-color: var(--primary-blue);
  color: white;
}

tr:nth-child(even) {
  background-color: #f9f9f9;
}

tr:hover {
  background-color: #f1f1f1;
}

h2 {
  color: var(--primary-blue);
  margin-top: 3rem;
  position: relative;
  padding-bottom: 0.5rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-blue), var(--primary-purple));
}

h3 {
  color: var(--primary-purple);
  margin-top: 2rem;
}

@media (max-width: 768px) {
  .tab-container {
    flex-direction: column;
  }
  
  .content-grid {
    grid-template-columns: 1fr;
  }
  
  .image-container {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .image-container {
    grid-template-columns: 1fr;
  }
  
  .header {
    padding: 1.5rem 0;
  }
  
  .main-container {
    padding: 0 1rem;
  }
  
  .article-container {
    padding: 1.5rem;
  }
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
}

.nav-link {
  padding: 0.5rem 1rem;
  background: linear-gradient(45deg, var(--primary-blue), var(--primary-purple));
  color: white;
  border-radius: 20px;
  text-decoration: none;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.nav-link:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.animation-demo {
  width: 100px;
  height: 100px;
  background: linear-gradient(45deg, var(--primary-blue), var(--primary-purple));
  border-radius: 8px;
  margin: 2rem auto;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(30, 47, 151, 0.4);
  }
  70% {
    transform: scale(1.05);
    box-shadow: 0 0 0 10px rgba(30, 47, 151, 0);
  }
  100% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(30, 47, 151, 0);
  }
}