:root {
    --primary: #0A2463;
    --secondary: #1E90FF;
    --accent: #FFA500;
    --light: #F5F5F5;
    --dark: #191919;
    --gradient: linear-gradient(135deg, var(--primary), var(--secondary));
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
  }

  body {
    background-color: var(--light);
    color: var(--dark);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  /* Header Styles */
  .header {
    background: var(--gradient);
    color: white;
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
    margin-bottom: 60px;
  }

  .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: 0.1;
    z-index: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
  }

  .header h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  }

  .header p {
    font-size: 1.2rem;
    margin-bottom: 30px;
  }

  /* Navigation */
  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(10, 36, 99, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .navbar-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    max-width: 1200px;
    margin: 0 auto;
  }

  .nav-logo {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
  }

  .nav-menu {
    display: flex;
    list-style: none;
  }

  .nav-item {
    margin-left: 30px;
  }

  .nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: var(--transition);
  }

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

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

  /* Article Styles */
  article {
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    padding: 50px;
    margin-bottom: 60px;
  }

  article h2 {
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: var(--gradient);
    border-radius: 2px;
  }

  article h3 {
    color: var(--secondary);
    font-size: 1.5rem;
    margin: 40px 0 20px;
  }

  article p {
    margin-bottom: 20px;
    font-size: 1.1rem;
  }

  article em {
    font-style: italic;
    color: var(--secondary);
  }

  article code {
    background-color: var(--light);
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    color: var(--primary);
  }

  /* Code Block Styles */
  pre {
    background-color: #282c34;
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    overflow: auto;
    box-shadow: var(--shadow);
  }

  pre code {
    color: #abb2bf;
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    display: block;
  }

  .language-css .token.property {
    color: #56b6c2;
  }

  .language-css .token.selector {
    color: #e06c75;
  }

  .language-css .token.punctuation {
    color: #abb2bf;
  }

  .language-css .token.string {
    color: #98c379;
  }

  /* Table Styles */
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: var(--shadow);
  }

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

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

  tr:nth-child(even) {
    background-color: rgba(30, 144, 255, 0.05);
  }

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

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

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }

  .gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
  }

  .gallery-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
  }

  /* Callout Box */
  .callout {
    background: linear-gradient(to right, rgba(30, 144, 255, 0.1), rgba(138, 43, 226, 0.1)));
    border-left: 4px solid var(--secondary);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
  }

  .callout p {
    margin: 0;
    color: var(--primary);
  }

  /* Footer */
  .footer {
    background-color: var(--primary);
    color: white;
    padding: 40px 0;
    text-align: center;
  }

  .footer p {
    margin-bottom: 20px;
  }

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

    .nav-menu {
      display: none;
    }

    article {
      padding: 30px;
    }

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

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

  .animate {
    animation: fadeIn 1s 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; }
  .text-accent { color: var(--accent); }
  .mt-40 { margin-top: 40px; }
  .mb-40 { margin-bottom: 40px; }
  .py-60 { padding: 60px 0; }