:root {
    --primary: #0d1b2a;
    --secondary: #1b263b;
    --accent: #00d2ff;
    --highlight: #39ff14;
    --text: #e0e1dd;
    --card-bg: rgba(27, 38, 59, 0.8);
  }

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

  body {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--text);
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    min-height: 100%;
    padding-top: 80px;
  }

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

  .reference-banner {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 10px 15px;
    border-radius: 20px;
    font-size: 14px;
    z-index: 1000;
    backdrop-filter: blur(5px);
  }

  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--primary);
    padding: 15px 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    display: flex;
    justify-content: center;
  }

  .nav-container {
    width: 100%;
    max-width: 1200px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
  }

  .nav-logo {
    color: var(--accent);
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
  }

  .nav-menu {
    display: flex;
    gap: 30px;
  }

  .nav-link {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
  }

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

  .nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s;
  }

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

  article {
    background: rgba(13, 27, 42, 0.7);
    border-radius: 15px;
    padding: 40px;
    margin: 40px 0;
    backdrop-filter: blur(10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  }

  h2 {
    font-size: 2rem;
    margin: 30px 0 20px;
    color: var(--accent);
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), transparent);
  }

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

  strong {
    color: var(--accent);
  }

  code {
    background: rgba(0, 210, 255, 0.1);
    color: var(--accent);
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
  }

  pre {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    overflow-x: auto;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.3);
    border-left: 3px solid var(--accent);
  }

  pre code {
    background: transparent;
    color: var(--text);
    padding: 0;
  }

  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 25px;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
  }

  .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--accent), var(--highlight));
  }

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

  .card-title {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--accent);
  }

  .card-content {
    margin-bottom: 15px;
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s;
  }

  .card:hover .card-img {
    transform: scale(1.03);
  }

  .divider {
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0, 210, 255, 0.5), transparent);
    margin: 40px 0;
  }

  .particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.1;
    background-image: url('https://images.gptkong.com/demo/sample1.png'), 
                     url('https://images.gptkong.com/demo/sample2.png');
    background-size: 300px;
    background-repeat: repeat;
    animation: particlesMove 100s linear infinite;
  }

  @keyframes particlesMove {
    0% { background-position: 0 0, 100px 100px; }
    100% { background-position: 1000px 1000px, 1100px 1100px; }
  }

  .gradient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(270deg, var(--primary), var(--secondary), var(--primary));
    background-size: 600% 600%;
    animation: gradientMove 15s ease infinite;
    z-index: -2;
  }

  @keyframes gradientMove {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }

  @media (max-width: 768px) {
    .nav-menu {
      gap: 15px;
    }
    
    article {
      padding: 25px;
    }
    
    h2 {
      font-size: 1.5rem;
    }
  }

  @media (max-width: 480px) {
    .nav-container {
      flex-direction: column;
      gap: 15px;
    }
    
    .nav-menu {
      flex-wrap: wrap;
      justify-content: center;
    }
    
    .card-grid {
      grid-template-columns: 1fr;
    }
  }