:root {
    --primary: #4A90E2;
    --primary-light: #6BA8F1;
    --secondary: #50E3C2;
    --accent: #F5A623;
    --text: #333;
    --text-light: #555;
    --bg: #f9f9f9;
    --card-bg: #fff;
    --border: #e0e0e0;
  }

  @font-face {
    font-family: 'Roboto';
    src: local('Roboto'), url(https://fonts.gstatic.com/s/roboto/v30/KFOmCnqEu92Fr1Mu4mxK.woff2) format('woff2');
    font-display: swap;
  }

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

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

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

  .header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    padding: 80px 0;
    text-align: center;
    color: white;
    position: relative;
    overflow: hidden;
    margin-bottom: 60px;
  }

  .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;
  }

  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  }

  .header p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto;
  }

  .notice {
    background-color: var(--accent);
    color: white;
    padding: 15px;
    text-align: center;
    font-weight: bold;
    margin-bottom: 40px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  }

  .article-container {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 40px;
    margin-bottom: 60px;
  }

  article {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
  }

  article h2 {
    color: var(--primary);
    font-size: 1.8rem;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
  }

  article h3 {
    color: var(--primary-light);
    font-size: 1.4rem;
    margin: 30px 0 15px;
  }

  article p {
    color: var(--text-light);
    margin-bottom: 20px;
    font-size: 1.05rem;
  }

  pre {
    background-color: #f5f7fa;
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    border-left: 4px solid var(--primary);
  }

  code {
    font-family: 'Roboto Mono', monospace;
    color: #2c3e50;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    box-shadow: 0 2px 3px rgba(0,0,0,0.1);
  }

  table th, table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border);
  }

  table th {
    background-color: var(--primary);
    color: white;
    font-weight: 500;
  }

  table tr:nth-child(even) {
    background-color: #f8f9fa;
  }

  .sidebar {
    position: sticky;
    top: 40px;
    align-self: start;
  }

  .sidebar-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
  }

  .sidebar-card h3 {
    color: var(--primary);
    font-size: 1.3rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
  }

  .image-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin-top: 20px;
  }

  .decorative-img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .decorative-img:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.15);
  }

  .tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
  }

  .tag {
    background-color: var(--primary-light);
    color: white;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
  }

  .footer {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 60px;
  }

  @media (max-width: 900px) {
    .article-container {
      grid-template-columns: 1fr;
    }
    
    .sidebar {
      position: static;
      order: -1;
    }
  }

  @media (max-width: 600px) {
    .header h1 {
      font-size: 2rem;
    }
    
    article {
      padding: 25px;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
  }

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

  article {
    animation: fadeIn 0.6s ease-out forwards;
  }

  .sidebar-card {
    animation: fadeIn 0.6s ease-out 0.2s forwards;
    opacity: 0;
  }

  /* Button styles for code examples */
  .btn-example {
    display: inline-block;
    background-color: var(--accent);
    color: white;
    padding: 10px 20px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    margin: 15px 0;
    transition: all 0.3s ease;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  }

  .btn-example:hover {
    background-color: #d48806;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
  }