:root {
    --primary: #032B44;
    --secondary: #FF7E00;
    --light: #F8F9FA;
    --gray: #E9ECEF;
    --dark: #212529;
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    color: var(--dark);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    line-height: 1.6;
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }

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

  .header {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(to right, var(--primary), #02333D);
    color: white;
    position: relative;
    overflow: hidden;
    border-radius: 0 0 20px 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  }

  .header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right/contain;
    opacity: 0.1;
    pointer-events: none;
  }

  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    position: relative;
    z-index: 2;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  }

  .header p {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    position: relative;
    z-index: 2;
  }

  .notice {
    background: rgba(255, 255, 255, 0.9);
    color: var(--primary);
    padding: 15px;
    border-radius: 8px;
    margin: 30px auto;
    max-width: 800px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    font-weight: bold;
    border-left: 5px solid var(--secondary);
  }

  article {
    background: white;
    border-radius: 15px;
    padding: 40px;
    margin: 40px 0;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
    position: relative;
    overflow: hidden;
  }

  article::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 150px;
    height: 150px;
    background: url('https://images.gptkong.com/demo/sample2.png') no-repeat center/contain;
    opacity: 0.1;
    z-index: 0;
  }

  h2, h3 {
    color: var(--primary);
    margin: 30px 0 20px;
    position: relative;
  }

  h2 {
    font-size: 1.8rem;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--gray);
  }

  h2::before {
    content: "";
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100px;
    height: 2px;
    background: var(--secondary);
  }

  h3 {
    font-size: 1.4rem;
  }

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

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

  .image-card {
    background: white;
    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;
  }

  .image-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
  }

  .image-card img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 12px 12px 0 0;
  }

  .image-card p {
    padding: 15px;
    font-size: 0.9rem;
    color: var(--dark);
  }

  pre {
    background: #f5f7fa;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    border-left: 4px solid var(--secondary);
    position: relative;
  }

  pre::before {
    content: "CSS";
    position: absolute;
    top: 0;
    right: 0;
    background: var(--secondary);
    color: white;
    padding: 2px 10px;
    font-size: 0.8rem;
    border-radius: 0 0 0 5px;
  }

  code {
    font-family: 'Courier New', monospace;
    background: rgba(255, 126, 0, 0.1);
    padding: 2px 5px;
    border-radius: 3px;
    color: var(--secondary);
    font-size: 0.95rem;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    overflow: hidden;
  }

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

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

  tr:nth-child(even) {
    background: var(--light);
  }

  tr:hover {
    background: rgba(255, 126, 0, 0.05);
  }

  .nav-tabs {
    display: flex;
    justify-content: center;
    margin: 40px 0;
    flex-wrap: wrap;
  }

  .nav-tabs a {
    padding: 12px 25px;
    margin: 0 10px;
    background: white;
    color: var(--primary);
    text-decoration: none;
    border-radius: 30px;
    font-weight: bold;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
  }

  .nav-tabs a:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  }

  .footer {
    text-align: center;
    padding: 30px;
    background: var(--primary);
    color: white;
    margin-top: 60px;
    border-radius: 20px 20px 0 0;
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2rem;
    }
    
    article {
      padding: 25px;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
    
    .nav-tabs a {
      margin: 5px;
      padding: 10px 15px;
    }
  }

  @media (max-width: 480px) {
    .header {
      padding: 40px 20px;
    }
    
    h2 {
      font-size: 1.5rem;
    }
    
    h3 {
      font-size: 1.2rem;
    }
    
    pre {
      padding: 15px;
      font-size: 0.85rem;
    }
  }

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

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

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

  .highlight {
    background: linear-gradient(90deg, rgba(255,126,0,0.1) 0%, rgba(255,126,0,0) 100%);
    padding: 2px 5px;
    border-radius: 3px;
  }