:root {
    --primary-color: #1A237E;
    --secondary-color: #FFFFFF;
    --background-color: #F5F5F5;
    --accent-color-green: #388E3C;
    --accent-color-orange: #FFA000;
    --text-color: #333333;
    --border-radius: 8px;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
  }

  @font-face {
    font-family: 'Roboto';
    src: local('Roboto'), local('Roboto-Regular');
    font-display: swap;
  }

  body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: 'Roboto', '思源黑体', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    letter-spacing: 0.5px;
    margin: 0;
    padding: 0;
    min-height: 100%;
  }

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 100px 20px 60px;
  }

  .header-banner {
    background: linear-gradient(135deg, var(--primary-color), #3949AB);
    color: var(--secondary-color);
    padding: 80px 20px;
    text-align: center;
    margin-bottom: 60px;
    border-radius: var(--border-radius);
    position: relative;
    overflow: hidden;
  }

  .header-banner::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
    background-size: contain;
    opacity: 0.1;
    z-index: 0;
  }

  .header-banner h1 {
    font-size: 2.8em;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  }

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

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

  article {
    background-color: var(--secondary-color);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 60px;
  }

  article h2 {
    color: var(--primary-color);
    font-size: 1.8em;
    margin-top: 40px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--accent-color-green);
  }

  article h3 {
    color: var(--primary-color);
    font-size: 1.4em;
    margin-top: 30px;
  }

  article p {
    margin-bottom: 20px;
  }

  pre {
    background: linear-gradient(45deg, #f8f9fa, #e9ecef);
    padding: 20px;
    border-radius: var(--border-radius);
    overflow-x: auto;
    margin: 25px 0;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.05);
    border-left: 4px solid var(--accent-color-green);
  }

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

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

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

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  }

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

  .gallery-item:hover img {
    transform: scale(1.05);
  }

  .nav-tabs {
    display: flex;
    flex-wrap: wrap;
    margin: 40px 0 20px;
    border-bottom: 1px solid #ddd;
  }

  .nav-tab {
    padding: 12px 20px;
    cursor: pointer;
    margin-right: 5px;
    background-color: #f1f1f1;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    transition: var(--transition);
  }

  .nav-tab.active {
    background-color: var(--primary-color);
    color: var(--secondary-color);
  }

  .tab-content {
    display: none;
    padding: 20px;
    background-color: var(--secondary-color);
    border-radius: 0 var(--border-radius) var(--border-radius) var(--border-radius);
    box-shadow: var(--box-shadow);
  }

  .tab-content.active {
    display: block;
  }

  .footer {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    padding: 40px 20px;
    text-align: center;
    margin-top: 60px;
  }

  @media (max-width: 768px) {
    .container {
      padding: 80px 15px 40px;
    }
    
    article {
      padding: 25px;
    }
    
    .header-banner h1 {
      font-size: 2em;
    }
    
    .image-gallery {
      grid-template-columns: 1fr;
    }
  }

  /* Animation */
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .animated {
    animation: fadeIn 0.6s ease forwards;
  }

  .delay-1 { animation-delay: 0.2s; }
  .delay-2 { animation-delay: 0.4s; }
  .delay-3 { animation-delay: 0.6s; }