:root {
    --primary: linear-gradient(135deg, #2c3e50, #1a2a3a);
    --secondary: #00c6ff;
    --accent: #0072ff;
    --text: #ecf0f1;
    --card-bg: rgba(44, 62, 80, 0.8);
    --neon-glow: 0 0 10px rgba(0, 198, 255, 0.7);
  }

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

  body {
    background: var(--primary);
    color: var(--text);
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    padding: 0;
    overflow-x: hidden;
  }

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

  header {
    text-align: center;
    padding: 40px 0;
    position: relative;
    overflow: hidden;
  }

  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: -1;
  }

  h1, h2, h3, h4 {
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--secondary);
    text-shadow: 0 0 5px rgba(0, 198, 255, 0.3);
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, #00c6ff, #0072ff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    display: inline-block;
  }

  h2 {
    font-size: 1.8rem;
    border-bottom: 2px solid var(--secondary);
    padding-bottom: 10px;
    margin-top: 40px;
  }

  h3 {
    font-size: 1.5rem;
    margin-top: 30px;
  }

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

  .hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 400px;
    position: relative;
    padding: 40px;
    border-radius: 15px;
    margin-bottom: 40px;
    overflow: hidden;
  }

  .hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample2.png') center/cover;
    opacity: 0.05;
    z-index: -1;
  }

  .hero-content {
    max-width: 800px;
    text-align: center;
    z-index: 1;
  }

  .notice {
    background: rgba(0, 198, 255, 0.1);
    border-left: 4px solid var(--secondary);
    padding: 15px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
    font-size: 0.9rem;
  }

  .grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
  }

  .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
  }

  .card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s;
  }

  .card:hover .card-image {
    transform: scale(1.03);
  }

  pre {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    overflow: auto;
    border-left: 4px solid var(--secondary);
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  code {
    color: var(--secondary);
    background: rgba(0, 198, 255, 0.1);
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
  }

  .button {
    display: inline-block;
    background: linear-gradient(45deg, var(--secondary), var(--accent));
    color: white;
    padding: 12px 25px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    margin: 10px 0;
    box-shadow: 0 4px 15px rgba(0, 198, 255, 0.4);
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    cursor: pointer;
  }

  .button:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(0, 198, 255, 0.6);
  }

  .coin-animation {
    width: 120px;
    height: 120px;
    background: radial-gradient(circle at 50% 50%, var(--secondary), var(--accent));
    border-radius: 50%;
    margin: 0 auto 30px;
    position: relative;
    animation: rotateCoin 5s linear infinite;
    box-shadow: var(--neon-glow);
  }

  @keyframes rotateCoin {
    from { transform: rotateY(0deg); }
    to { transform: rotateY(360deg); }
  }

  .nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin: 30px 0;
  }

  .nav-link {
    color: var(--text);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 30px;
    background: rgba(255, 255, 255, 0.1);
    transition: all 0.3s;
  }

  .nav-link:hover {
    background: rgba(0, 198, 255, 0.2);
    color: var(--secondary);
    box-shadow: var(--neon-glow);
  }

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

  .gallery-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .gallery-image:hover {
    transform: scale(1.03);
    box-shadow: 0 8px 25px rgba(0, 198, 255, 0.4);
  }

  footer {
    text-align: center;
    padding: 30px;
    margin-top: 50px;
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid rgba(0, 198, 255, 0.2);
  }

  @media (max-width: 768px) {
    .grid-container {
      grid-template-columns: 1fr;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.5rem;
    }
    
    .hero {
      min-height: 300px;
      padding: 20px;
    }
  }

  @media (max-width: 480px) {
    .button, .nav-link {
      padding: 8px 16px;
    }
    
    .coin-animation {
      width: 80px;
      height: 80px;
    }
  }