:root {
    --primary: #2c3e50;
    --secondary: #34495e;
    --accent: #e67e22;
    --text: #333;
    --light: #ecf0f1;
    --gradient: linear-gradient(135deg, #3498db, #2c3e50);
  }

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&display=swap');
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    color: var(--text);
    background: linear-gradient(to bottom, #f5f7fa 0%, #e4e8eb 100%);
    line-height: 1.6;
    overflow-x: hidden;
  }

  .reference-banner {
    position: fixed;
    top: 0;
    right: 0;
    background: var(--accent);
    color: white;
    padding: 8px 16px;
    font-size: 12px;
    z-index: 1000;
    border-bottom-left-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  .container {
    max-width: 1200px;
    margin: 60px auto 40px;
    padding: 0 20px;
  }

  header {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
    padding: 40px 0;
  }

  header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
  }

  h1, h2, h3, h4 {
    font-weight: 500;
    color: var(--primary);
    margin-bottom: 20px;
    position: relative;
  }

  h1 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  h2 {
    font-size: 1.8rem;
    padding-bottom: 10px;
    border-bottom: 2px solid rgba(44, 62, 80, 0.1);
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100px;
    height: 2px;
    background: var(--accent);
  }

  h3 {
    font-size: 1.4rem;
    margin-top: 40px;
  }

  p {
    margin-bottom: 20px;
    font-size: 1.05rem;
  }

  article {
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    padding: 40px;
    position: relative;
    overflow: hidden;
  }

  article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: var(--gradient);
  }

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

  .decorative-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .decorative-img:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
  }

  pre {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    border-left: 4px solid var(--accent);
    font-size: 0.9rem;
    line-height: 1.5;
  }

  code {
    font-family: 'Roboto Mono', monospace;
    color: #e83e8c;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  }

  th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
  }

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

  tr:nth-child(even) {
    background: #f9f9f9;
  }

  tr:hover {
    background: #f1f1f1;
  }

  .nav-tabs {
    display: flex;
    margin-bottom: 30px;
    border-bottom: 1px solid #eee;
  }

  .nav-tabs a {
    padding: 10px 20px;
    margin-right: 5px;
    background: #f5f5f5;
    color: var(--text);
    text-decoration: none;
    border-radius: 5px 5px 0 0;
    transition: all 0.3s;
  }

  .nav-tabs a:hover {
    background: #eee;
  }

  .nav-tabs a.active {
    background: var(--primary);
    color: white;
  }

  .fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s, transform 0.6s;
  }

  .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
  }

  @media (max-width: 768px) {
    .container {
      padding: 0 15px;
    }
    
    article {
      padding: 30px 20px;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.5rem;
    }
    
    .image-grid {
      grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
  }

  @media (max-width: 480px) {
    h1 {
      font-size: 1.8rem;
    }
    
    h2 {
      font-size: 1.3rem;
    }
    
    pre {
      padding: 15px;
      font-size: 0.8rem;
    }
  }

  /* Animations */
  @keyframes float {
    0%, 100% {
      transform: translateY(0);
    }
    50% {
      transform: translateY(-10px);
    }
  }

  .floating {
    animation: float 3s ease-in-out infinite;
  }

  @keyframes pulse {
    0%, 100% {
      opacity: 1;
    }
    50% {
      opacity: 0.5;
    }
  }

  .pulse {
    animation: pulse 2s ease-in-out infinite;
  }