:root {
    --primary: #1E2740;
    --secondary: #5C2D91;
    --accent: #FFA726;
    --text: #E0E0E0;
    --bg: #121212;
    --card-bg: #2C3E50;
    --gradient: linear-gradient(135deg, #5C2D91 0%, #7A38F2 100%);
  }

  @font-face {
    font-family: 'Roboto Bold';
    src: local('Roboto Bold'), local('Roboto-Bold');
  }

  @font-face {
    font-family: 'Open Sans Regular';
    src: local('Open Sans Regular'), local('OpenSans-Regular');
  }

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

  body {
    font-family: 'Open Sans Regular', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    overflow-x: hidden;
  }

  .tech-banner {
    position: relative;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient);
    margin-bottom: 60px;
    overflow: hidden;
  }

  .tech-banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover;
    opacity: 0.2;
  }

  .banner-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 0 20px;
    max-width: 800px;
  }

  h1 {
    font-family: 'Roboto Bold', sans-serif;
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.3);
    color: white;
  }

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

  .reference-note {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(0,0,0,0.7);
    padding: 10px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    z-index: 1000;
  }

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

  article {
    background: rgba(30, 39, 64, 0.5);
    border-radius: 15px;
    padding: 40px;
    margin-bottom: 60px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    backdrop-filter: blur(10px);
  }

  article h2 {
    font-family: 'Roboto Bold', sans-serif;
    font-size: 2rem;
    margin-bottom: 30px;
    color: white;
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 3px;
    background: var(--accent);
  }

  article h3 {
    font-family: 'Roboto Bold', sans-serif;
    font-size: 1.5rem;
    margin: 30px 0 20px;
    color: white;
  }

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

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

  .tech-image {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .tech-image:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
  }

  .tech-image img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 10px;
  }

  pre {
    background: #1E2740;
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
    position: relative;
  }

  pre::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 30px;
    background: rgba(0,0,0,0.2);
    border-radius: 8px 8px 0 0;
  }

  code {
    font-family: 'Courier New', monospace;
    color: #BDC3C7;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  .highlight {
    background: var(--gradient);
    padding: 2px 5px;
    border-radius: 3px;
    color: white;
  }

  .nav-links {
    position: sticky;
    top: 20px;
    margin-bottom: 40px;
    background: rgba(30, 39, 64, 0.8);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
  }

  .nav-links h3 {
    font-family: 'Roboto Bold', sans-serif;
    margin-bottom: 15px;
    color: var(--accent);
  }

  .nav-links ul {
    list-style: none;
  }

  .nav-links li {
    margin-bottom: 10px;
  }

  .nav-links a {
    color: var(--text);
    text-decoration: none;
    transition: color 0.3s;
    display: block;
    padding: 5px 0;
    position: relative;
  }

  .nav-links a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s;
  }

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

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

  .content-wrapper {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 30px;
  }

  @media (max-width: 900px) {
    .content-wrapper {
      grid-template-columns: 1fr;
    }

    .nav-links {
      position: static;
    }
  }

  @media (max-width: 600px) {
    .tech-banner {
      height: 300px;
    }

    h1 {
      font-size: 2rem;
    }

    article {
      padding: 25px;
    }

    article h2 {
      font-size: 1.5rem;
    }

    article h3 {
      font-size: 1.3rem;
    }

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