:root {
    --primary-gradient: linear-gradient(135deg, #667eea, #764ba2);
    --secondary-gradient: linear-gradient(45deg, #6a5acd, #9370db);
    --accent-color: #ff7f50;
    --text-light: #ffffff;
    --text-dark: #333333;
    --bg-light: #f8f9fa;
    --bg-dark: #1a1a2e;
    --card-shadow: 0 10px 20px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Montserrat', sans-serif;
  }

  body {
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
  }

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

  /* Hero Section */
  .hero {
    background: var(--primary-gradient);
    color: var(--text-light);
    padding: 120px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample3.png') no-repeat center center;
    background-size: cover;
    opacity: 0.1;
  }

  .hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  }

  .hero p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 30px;
    position: relative;
    z-index: 1;
  }

  .notice {
    background-color: rgba(255,255,255,0.2);
    padding: 15px;
    border-radius: 8px;
    display: inline-block;
    margin-top: 30px;
    backdrop-filter: blur(5px);
    position: relative;
    z-index: 1;
  }

  /* Navigation */
  .navbar {
    position: sticky;
    top: 0;
    background: var(--primary-gradient);
    padding: 15px 0;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: var(--transition);
  }

  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .nav-links {
    display: flex;
    gap: 30px;
  }

  .nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
  }

  .nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: var(--transition);
  }

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

  /* Main Content */
  main {
    padding: 60px 0;
  }

  article {
    background-color: white;
    border-radius: 12px;
    padding: 40px;
    box-shadow: var(--card-shadow);
    margin-bottom: 40px;
  }

  article h2 {
    font-size: 2rem;
    margin-bottom: 30px;
    color: #6A5ACD;
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 4px;
    background: var(--secondary-gradient);
    border-radius: 2px;
  }

  article h3 {
    font-size: 1.5rem;
    margin: 30px 0 20px;
    color: #764ba2;
  }

  article p {
    margin-bottom: 20px;
    font-size: 1.1rem;
  }

  article code {
    background-color: #f5f5f5;
    padding: 2px 5px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
  }

  pre {
    background-color: #282c34;
    color: #abb2bf;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 20px 0;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  pre code {
    background-color: transparent;
    padding: 0;
    border-radius: 0;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
  }

  th {
    background: var(--secondary-gradient);
    color: white;
  }

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

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

  /* Image Gallery */
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .gallery-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
  }

  .gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
  }

  .gallery-item img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    display: block;
  }

  /* Cards */
  .card-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
  }

  .card h4 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: #6A5ACD;
  }

  /* Footer */
  footer {
    background: var(--bg-dark);
    color: var(--text-light);
    padding: 40px 0;
    text-align: center;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin: 20px 0;
  }

  .footer-links a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
  }

  .footer-links a:hover {
    color: var(--accent-color);
  }

  /* Responsive */
  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.2rem;
    }
    
    .nav-links {
      gap: 15px;
    }
    
    article {
      padding: 30px 20px;
    }
    
    .card-container {
      grid-template-columns: 1fr;
    }
  }

  @media (max-width: 480px) {
    .hero {
      padding: 80px 0;
    }
    
    .hero h1 {
      font-size: 1.8rem;
    }
    
    .nav-container {
      flex-direction: column;
      gap: 15px;
    }
    
    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }
  }

  /* Animations */
  @keyframes float {
    0%, 100% {
      transform: translateY(0);
    }
    50% {
      transform: translateY(-20px);
    }
  }

  .floating {
    animation: float 6s ease-in-out infinite;
  }

  /* Scroll Indicator */
  .scroll-indicator {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-gradient);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    opacity: 0;
    transition: var(--transition);
    z-index: 999;
  }

  .scroll-indicator.visible {
    opacity: 1;
  }