:root {
    --primary-color: #8B4513;
    --secondary-color: #F5DEB3;
    --accent-color: #1E90FF;
    --dark-accent: #556B2F;
    --light-accent: #C0C0C0;
    --text-dark: #333;
    --text-light: #f8f8f8;
    --transition: all 0.3s ease;
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    color: var(--text-dark);
    background: linear-gradient(135deg, var(--secondary-color) 0%, rgba(245,222,179,0.8) 100%);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  header {
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--dark-accent) 100%);
    color: var(--text-light);
    padding: 2rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 20px 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') center/cover no-repeat;
    opacity: 0.2;
    z-index: 0;
  }

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

  h1, h2, h3, h4 {
    font-family: 'Playfair Display', serif;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
  }

  h1 {
    font-size: 2.8rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
  }

  h2 {
    font-size: 2.2rem;
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
    margin-top: 3rem;
  }

  h3 {
    font-size: 1.8rem;
    margin-top: 2rem;
    color: var(--dark-accent);
  }

  p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
  }

  .tech-notice {
    background: rgba(30, 144, 255, 0.1);
    border-left: 4px solid var(--accent-color);
    padding: 1rem;
    margin: 2rem 0;
    font-style: italic;
    border-radius: 0 4px 4px 0;
  }

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
  }

  .decorative-img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    transition: var(--transition);
  }

  .decorative-img:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
  }

  pre {
    background: rgba(0,0,0,0.05);
    border-left: 4px solid var(--accent-color);
    padding: 1.5rem;
    margin: 2rem 0;
    overflow-x: auto;
    border-radius: 0 4px 4px 0;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.5;
  }

  code {
    background: rgba(0,0,0,0.05);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  }

  th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid rgba(0,0,0,0.1);
  }

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

  tr:nth-child(even) {
    background-color: rgba(245,222,179,0.3);
  }

  tr:hover {
    background-color: rgba(30,144,255,0.1);
  }

  .nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 2rem 0;
  }

  .nav-link {
    padding: 0.8rem 1.5rem;
    background: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: var(--transition);
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  }

  .nav-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
  }

  footer {
    background: linear-gradient(90deg, var(--dark-accent) 0%, var(--primary-color) 100%);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
  }

  @media (max-width: 768px) {
    h1 {
      font-size: 2.2rem;
    }
    h2 {
      font-size: 1.8rem;
    }
    h3 {
      font-size: 1.5rem;
    }
    .image-grid {
      grid-template-columns: 1fr;
    }
  }

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

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

  .highlight {
    background: linear-gradient(90deg, rgba(30,144,255,0.2) 0%, rgba(30,144,255,0) 100%);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
  }