:root {
    --primary: #1e3c72;
    --secondary: #2a5298;
    --accent: #ffcc00;
    --light: rgba(255,255,255,0.8);
    --dark: #0a1220;
    --text: #e0e0e0;
    --highlight: #ffd700;
  }

  @font-face {
    font-family: 'Roboto';
    src: local('Roboto'), url(https://fonts.gstatic.com/s/roboto/v30/KFOmCnqEu92Fr1Mu4mxK.woff2) format('woff2');
    font-display: swap;
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.8;
    color: var(--text);
    background: radial-gradient(ellipse at bottom, var(--dark) 0%, #090a0f 100%);
    overflow-x: hidden;
    min-height: 100%;
    padding-bottom: 100px;
  }

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

  .header {
    position: relative;
    padding: 80px 0 120px;
    text-align: center;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
    margin-bottom: 80px;
    overflow: hidden;
  }

  .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 h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    text-shadow: 0 5px 15px rgba(0,0,0,0.3);
    background: linear-gradient(to right, var(--light), var(--highlight));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  .header p {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.2rem;
    position: relative;
    z-index: 1;
    color: var(--light);
  }

  .reference-badge {
    position: fixed;
    top: 20px;
    right: 20px;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
    padding: 10px 20px;
    border-radius: 30px;
    font-size: 14px;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    border: 1px solid rgba(255,255,255,0.1);
  }

  .nav-container {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(10,18,32,0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }

  .nav {
    display: flex;
    justify-content: center;
    padding: 15px 0;
  }

  .nav a {
    color: var(--light);
    text-decoration: none;
    margin: 0 15px;
    padding: 8px 15px;
    border-radius: 20px;
    transition: all 0.3s ease;
    position: relative;
    font-weight: 500;
  }

  .nav a:hover {
    color: var(--highlight);
    transform: translateY(-2px);
  }

  .nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--highlight);
    transition: all 0.3s ease;
    transform: translateX(-50%);
  }

  .nav a:hover::after {
    width: 60%;
  }

  article {
    background: rgba(255,255,255,0.05);
    border-radius: 15px;
    padding: 50px;
    margin: 40px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.05);
    position: relative;
    overflow: hidden;
  }

  article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample2.png') center/cover no-repeat;
    opacity: 0.03;
    z-index: 0;
  }

  article > * {
    position: relative;
    z-index: 1;
  }

  article h2 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    color: var(--highlight);
    text-shadow: 0 2px 10px rgba(255,215,0,0.3);
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 3px;
    background: linear-gradient(to right, var(--highlight), transparent);
    border-radius: 3px;
  }

  article h3 {
    font-size: 1.8rem;
    margin: 40px 0 20px;
    color: var(--light);
  }

  article p {
    margin-bottom: 25px;
    font-size: 1.1rem;
    line-height: 1.8;
  }

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

  .image-card {
    background: rgba(255,255,255,0.05);
    border-radius: 10px;
    overflow: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    border: 1px solid rgba(255,255,255,0.1);
  }

  .image-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.3);
  }

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

  .image-card .caption {
    padding: 20px;
    font-size: 0.9rem;
    color: var(--light);
    opacity: 0.8;
  }

  pre {
    background: rgba(0,0,0,0.3);
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    overflow: auto;
    border-left: 4px solid var(--highlight);
    font-family: 'Roboto Mono', monospace;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--highlight);
    color: var(--dark);
    padding: 5px 10px;
    font-size: 12px;
    border-radius: 0 0 0 5px;
    font-weight: bold;
  }

  code {
    font-family: 'Roboto Mono', monospace;
    background: rgba(255,215,0,0.1);
    padding: 2px 5px;
    border-radius: 3px;
    color: var(--highlight);
    font-size: 0.9em;
  }

  .star {
    position: absolute;
    background: white;
    border-radius: 50%;
    width: 2px;
    height: 2px;
    animation: twinkle 2s infinite;
  }

  @keyframes twinkle {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
  }

  .button {
    display: inline-block;
    background: linear-gradient(145deg, var(--accent), #ff9900);
    border: none;
    border-radius: 5px;
    box-shadow:  5px 5px 15px rgba(180,136,8,0.5),
                -5px -5px 15px rgba(255,214,51,0.3);
    color: var(--dark);
    padding: 15px 30px;
    font-size: 18px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin: 20px 0;
    font-weight: bold;
    text-decoration: none;
  }

  .button:hover {
    transform: translateY(-3px);
    box-shadow:  8px 8px 20px rgba(180,136,8,0.6),
                -8px -8px 20px rgba(255,214,51,0.4);
  }

  .button:active {
    transform: translateY(1px);
    box-shadow:  2px 2px 10px rgba(180,136,8,0.5),
                -2px -2px 10px rgba(255,214,51,0.3);
  }

  .footer {
    text-align: center;
    padding: 50px 0;
    margin-top: 100px;
    position: relative;
  }

  .footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 1px;
    background: linear-gradient(to right, transparent, rgba(255,255,255,0.3), transparent);
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2.5rem;
    }
    
    .header p {
      font-size: 1rem;
    }
    
    article {
      padding: 30px 20px;
    }
    
    article h2 {
      font-size: 2rem;
    }
    
    article h3 {
      font-size: 1.5rem;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
    
    .nav {
      flex-wrap: wrap;
    }
    
    .nav a {
      margin: 5px;
      padding: 5px 10px;
    }
  }

  @media (min-width: 769px) and (max-width: 1024px) {
    .header h1 {
      font-size: 3rem;
    }
    
    .image-grid {
      grid-template-columns: repeat(2, 1fr);
    }
  }

  /* Generate random stars */
  .star:nth-child(1) { top: 10%; left: 20%; animation-delay: 0s; }
  .star:nth-child(2) { top: 25%; left: 80%; animation-delay: 0.5s; }
  .star:nth-child(3) { top: 40%; left: 50%; animation-delay: 1s; }
  .star:nth-child(4) { top: 60%; left: 30%; animation-delay: 1.5s; }
  .star:nth-child(5) { top: 75%; left: 70%; animation-delay: 2s; }
  .star:nth-child(6) { top: 90%; left: 10%; animation-delay: 2.5s; }