:root {
    --primary-color: #3F51B5;
    --accent-color1: #FFC67D;
    --accent-color2: #8A2BE2;
    --background-color: #F5F5F5;
    --text-color: #333;
    --light-text: #777;
  }

  @font-face {
    font-family: 'Helvetica Neue';
    src: local('Helvetica Neue'), local('HelveticaNeue');
  }

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

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

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

  .header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color2) 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
    margin-bottom: 60px;
    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: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
  }

  h1 {
    font-family: 'Helvetica Neue', sans-serif;
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  }

  .subtitle {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 30px;
  }

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

  article {
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    padding: 50px;
    margin-bottom: 60px;
  }

  article h2 {
    color: var(--primary-color);
    font-family: 'Helvetica Neue', sans-serif;
    font-size: 2rem;
    margin: 40px 0 20px;
    position: relative;
    padding-left: 20px;
  }

  article h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 70%;
    width: 5px;
    background: linear-gradient(to bottom, var(--primary-color), var(--accent-color2));
    border-radius: 5px;
  }

  article h3 {
    color: var(--accent-color2);
    font-size: 1.5rem;
    margin: 30px 0 15px;
  }

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

  color {
    color: var(--primary-color);
    font-weight: bold;
  }

  pre {
    background: linear-gradient(145deg, #f8f9fa, #e9ecef);
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
  }

  code {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: #333;
  }

  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .gallery-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
  }

  .gallery-item img {
    width: 100%;
    height: auto;
    display: block;
  }

  .nav-links {
    position: sticky;
    top: 20px;
    margin-bottom: 40px;
  }

  .nav-links h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
  }

  .nav-links ul {
    list-style: none;
    background: white;
    border-radius: 8px;
    padding: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  }

  .nav-links li {
    margin: 10px 0;
  }

  .nav-links a {
    color: var(--text-color);
    text-decoration: none;
    display: block;
    padding: 8px 15px;
    border-radius: 5px;
    transition: all 0.3s ease;
  }

  .nav-links a:hover {
    background-color: rgba(63, 81, 181, 0.1);
    color: var(--primary-color);
  }

  .footer {
    text-align: center;
    padding: 30px 0;
    color: var(--light-text);
    font-size: 0.9rem;
  }

  @media (max-width: 768px) {
    .header {
      padding: 40px 0;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    article {
      padding: 30px;
    }
    
    article h2 {
      font-size: 1.5rem;
    }
    
    article h3 {
      font-size: 1.2rem;
    }
    
    .gallery {
      grid-template-columns: 1fr;
    }
  }