:root {
    --primary-color: #a89f91;
    --secondary-color: #c3b299;
    --accent-color: #e67e22;
    --background-color: #f5f2f2;
    --text-color: #333;
    --light-text: #777;
    --border-radius: 12px;
    --box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

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

  body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--background-color);
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }

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

  /* Header Styles */
  .header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
    margin-bottom: 3rem;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    box-shadow: var(--box-shadow);
  }

  .header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample3.png') no-repeat;
    background-size: cover;
    opacity: 0.1;
    z-index: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 2rem;
  }

  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  }

  .header p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0.9;
  }

  /* Navigation */
  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    margin-bottom: 2rem;
  }

  .logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    display: flex;
    align-items: center;
  }

  .logo img {
    width: 40px;
    height: 40px;
    margin-right: 10px;
    border-radius: 50%;
  }

  .nav-links {
    display: flex;
    gap: 1.5rem;
  }

  .nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
  }

  .nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: var(--transition);
  }

  .nav-links a:hover::after {
    width: 100%;
  }

  /* Main Content */
  .main-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
  }

  article {
    background: white;
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    position: relative;
    overflow: hidden;
  }

  article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
  }

  article h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 0.5rem;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--accent-color);
    border-radius: 3px;
  }

  article h3 {
    font-size: 1.4rem;
    margin: 2rem 0 1rem;
    color: var(--secondary-color);
  }

  article p {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
    line-height: 1.7;
  }

  article span {
    font-weight: bold;
    color: var(--accent-color);
  }

  /* Code Blocks */
  pre {
    background: #2d2d2d;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow: auto;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent-color);
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 0 0 0 var(--border-radius);
    font-size: 0.8rem;
    font-weight: bold;
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    color: #f8f8f2;
    font-size: 0.95rem;
  }

  /* Image Gallery */
  .image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
  }

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

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.15);
  }

  .gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
  }

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

  /* Sidebar */
  .sidebar {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 2rem;
  }

  .sidebar h3 {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 0.5rem;
  }

  .sidebar h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--accent-color);
  }

  .tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
  }

  .tag {
    background: #f0f0f0;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--light-text);
    transition: var(--transition);
  }

  .tag:hover {
    background: var(--accent-color);
    color: white;
  }

  /* Footer */
  .footer {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 3rem 0;
    margin-top: 3rem;
    text-align: center;
  }

  .footer p {
    opacity: 0.8;
    margin-bottom: 1rem;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
  }

  .footer-links a {
    color: white;
    text-decoration: none;
    transition: var(--transition);
  }

  .footer-links a:hover {
    color: var(--accent-color);
  }

  .copyright {
    font-size: 0.9rem;
    opacity: 0.7;
  }

  /* Responsive Design */
  @media (max-width: 992px) {
    .nav-container {
      flex-direction: column;
      gap: 1rem;
    }

    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2rem;
    }

    article {
      padding: 1.5rem;
    }

    .image-gallery {
      grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
  }

  @media (max-width: 576px) {
    .header {
      padding: 1.5rem 0;
    }

    .header h1 {
      font-size: 1.8rem;
    }

    .header p {
      font-size: 1rem;
    }

    article h2 {
      font-size: 1.5rem;
    }

    article h3 {
      font-size: 1.2rem;
    }

    .image-gallery {
      grid-template-columns: 1fr;
    }
  }

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

  .fade-in {
    animation: fadeIn 0.6s ease-out forwards;
  }

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

  /* Utility Classes */
  .text-center { text-align: center; }
  .mt-1 { margin-top: 0.5rem; }
  .mt-2 { margin-top: 1rem; }
  .mt-3 { margin-top: 1.5rem; }
  .mt-4 { margin-top: 2rem; }
  .mb-1 { margin-bottom: 0.5rem; }
  .mb-2 { margin-bottom: 1rem; }
  .mb-3 { margin-bottom: 1.5rem; }
  .mb-4 { margin-bottom: 2rem; }
  .py-2 { padding-top: 1rem; padding-bottom: 1rem; }
  .py-3 { padding-top: 1.5rem; padding-bottom: 1.5rem; }
  .px-2 { padding-left: 1rem; padding-right: 1rem; }
  .px-3 { padding-left: 1.5rem; padding-right: 1.5rem; }

  /* Notice */
  .notice {
    background: rgba(230, 126, 34, 0.1);
    border-left: 4px solid var(--accent-color);
    padding: 1rem;
    margin: 2rem 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
  }