:root {
    --primary-color: #007BFF;
    --accent-color: #FFC107;
    --background-color: #F8F9FA;
    --text-color: #333333;
    --dark-bg: #1e1e1e;
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  @import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&family=Roboto:wght@300;400;500&display=swap');

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

  body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
    color: var(--text-color);
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  /* Header Styles */
  .header {
    background: linear-gradient(90deg, var(--primary-color) 0%, #0066cc 100%);
    color: white;
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 12px 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;
    background-size: cover;
    opacity: 0.05;
    z-index: 0;
  }

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

  .header h1 {
    font-family: 'Montserrat', sans-serif;
    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 2rem;
  }

  .notice {
    background-color: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 1rem;
    border-radius: 8px;
    display: inline-block;
    margin-top: 1rem;
    font-weight: 500;
  }

  /* Navigation */
  .nav-container {
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
  }

  .nav {
    display: flex;
    justify-content: center;
    padding: 1rem 0;
  }

  .nav a {
    color: var(--primary-color);
    text-decoration: none;
    margin: 0 1.5rem;
    font-weight: 500;
    font-size: 1.1rem;
    position: relative;
    transition: var(--transition);
  }

  .nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: var(--transition);
  }

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

  /* Main Content */
  .main-content {
    padding: 3rem 0;
  }

  .article-container {
    background: white;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    padding: 3rem;
    margin-bottom: 3rem;
  }

  article h2 {
    color: var(--primary-color);
    font-family: 'Montserrat', sans-serif;
    font-size: 2rem;
    margin-bottom: 1.5rem;
    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 {
    color: var(--primary-color);
    font-family: 'Montserrat', sans-serif;
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
  }

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

  /* Code Blocks */
  pre {
    background: #f8f9fa;
    border-left: 4px solid var(--primary-color);
    border-radius: 4px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow: auto;
    font-family: 'Roboto Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  code {
    background: rgba(0, 123, 255, 0.1);
    color: var(--primary-color);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Roboto Mono', monospace;
    font-size: 0.9rem;
  }

  /* Tables */
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  }

  th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
  }

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

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

  tr:hover {
    background-color: #f1f1f1;
  }

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

  .gallery-item {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
  }

  .gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: var(--transition);
  }

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

  /* Footer */
  .footer {
    background: linear-gradient(135deg, #2c3e50 0%, #1e2a38 100%);
    color: white;
    padding: 3rem 0;
    text-align: center;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
  }

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

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

  .footer-links a {
    color: rgba(255, 255, 255, 0.8);
    margin: 0 1rem;
    text-decoration: none;
    transition: var(--transition);
  }

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

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

    .nav {
      flex-direction: column;
      align-items: center;
    }

    .nav a {
      margin: 0.5rem 0;
    }

    .article-container {
      padding: 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; }

  /* Theme Toggle */
  .theme-toggle {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--primary-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    transition: var(--transition);
  }

  .theme-toggle:hover {
    transform: scale(1.1);
  }

  /* Dark Theme */
  body.dark-theme {
    background: var(--dark-bg);
    color: #f0f0f0;
  }

  body.dark-theme .article-container,
  body.dark-theme pre {
    background: #2a2a2a;
  }

  body.dark-theme code {
    background: rgba(0, 123, 255, 0.2);
  }

  body.dark-theme table th {
    background: #333;
  }

  body.dark-theme tr:nth-child(even) {
    background: #333;
  }

  body.dark-theme tr:hover {
    background: #444;
  }