:root {
    --primary: linear-gradient(135deg, #8e44ad, #1abc9c);
    --secondary: rgba(255, 255, 255, 0.2);
    --accent: #f39c12;
    --text: #2c3e50;
    --light: #ecf0f1;
    --dark: #2c3e50;
    --radius: 15px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
  }

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

  body {
    background: var(--primary);
    color: var(--text);
    line-height: 1.6;
    padding: 0;
    margin: 0;
    overflow-x: hidden;
    min-height: 100%;
  }

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

  header {
    text-align: center;
    padding: 60px 20px;
    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 no-repeat;
    opacity: 0.1;
    z-index: -1;
  }

  h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    background: linear-gradient(to right, #8e44ad, #1abc9c);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  }

  .subtitle {
    font-size: 1.2rem;
    color: var(--light);
    max-width: 700px;
    margin: 0 auto 30px;
  }

  .notice {
    background: rgba(255, 255, 255, 0.9);
    color: var(--dark);
    padding: 15px;
    border-radius: var(--radius);
    margin: 20px 0;
    box-shadow: var(--shadow);
    text-align: center;
    font-weight: bold;
  }

  article {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    padding: 40px;
    margin: 40px 0;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
  }

  article::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
    animation: rotate 20s linear infinite;
    z-index: -1;
  }

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

  h2 {
    font-size: 2rem;
    margin: 30px 0 20px;
    color: var(--dark);
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 3px;
    background: var(--primary);
  }

  h3 {
    font-size: 1.5rem;
    margin: 25px 0 15px;
    color: var(--dark);
  }

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

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }

  .image-card {
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }

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

  .image-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
  }

  .image-card .caption {
    padding: 15px;
    background: white;
  }

  pre {
    background: rgba(44, 62, 80, 0.9);
    color: #ecf0f1;
    padding: 20px;
    border-radius: var(--radius);
    margin: 20px 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    box-shadow: var(--shadow);
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent);
    color: white;
    padding: 5px 10px;
    border-radius: 0 var(--radius) 0 var(--radius);
    font-size: 0.8rem;
  }

  code {
    font-family: 'Courier New', monospace;
    background: rgba(44, 62, 80, 0.1);
    padding: 2px 5px;
    border-radius: 3px;
    color: #e74c3c;
  }

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

  .nav-link {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(5px);
    padding: 10px 20px;
    border-radius: 50px;
    color: white;
    text-decoration: none;
    transition: var(--transition);
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  }

  .nav-link:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-3px);
  }

  footer {
    text-align: center;
    padding: 30px;
    color: var(--light);
    font-size: 0.9rem;
  }

  @media (max-width: 768px) {
    h1 {
      font-size: 2rem;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
    
    article {
      padding: 20px;
    }
    
    pre {
      padding: 15px;
      font-size: 0.9rem;
    }
  }

  /* Additional decorative elements */
  .decorative-circle {
    position: absolute;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
    animation: float 6s ease-in-out infinite;
    z-index: -1;
  }

  .circle-1 {
    top: 10%;
    left: 5%;
    animation-delay: 0s;
  }

  .circle-2 {
    bottom: 15%;
    right: 8%;
    animation-delay: 1s;
    width: 150px;
    height: 150px;
  }

  @keyframes float {
    0% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
    100% { transform: translateY(0) rotate(0deg); }
  }