:root {
    --primary: #1e3c72;
    --secondary: #2a5298;
    --accent: #00bfff;
    --light: rgba(255,255,255,0.9);
    --dark: rgba(0,0,0,0.8);
    --gradient: linear-gradient(135deg, var(--primary), var(--secondary));
  }

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

  body {
    background: var(--gradient);
    color: var(--light);
    line-height: 1.6;
    min-height: 100%;
    position: relative;
    overflow-x: hidden;
  }

  .header {
    text-align: center;
    padding: 2rem;
    background: rgba(30, 60, 114, 0.7);
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--accent);
  }

  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
  }

  .header p {
    font-size: 1.1rem;
    opacity: 0.9;
  }

  .reference {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(0,0,0,0.7);
    padding: 10px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    z-index: 1000;
  }

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

  article {
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 3rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  }

  article h2 {
    color: var(--accent);
    margin: 2rem 0 1rem;
    font-size: 1.8rem;
    position: relative;
    padding-bottom: 10px;
  }

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

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

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 2rem 0;
  }

  .image-grid img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .image-grid img:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.4);
  }

  pre {
    background: rgba(0,0,0,0.3);
    border-radius: 10px;
    padding: 1.5rem;
    margin: 2rem 0;
    overflow: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    left: 0;
    background: var(--accent);
    color: white;
    padding: 3px 10px;
    border-radius: 0 0 5px 0;
    font-size: 0.8rem;
  }

  code {
    font-family: 'Courier New', monospace;
    background: rgba(0,0,0,0.2);
    padding: 2px 5px;
    border-radius: 3px;
    font-size: 0.9rem;
  }

  .nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin: 2rem 0;
  }

  .nav-links a {
    color: var(--light);
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 20px;
    background: rgba(255,255,255,0.1);
    transition: all 0.3s ease;
  }

  .nav-links a:hover {
    background: var(--accent);
    transform: translateY(-3px);
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2rem;
    }
    
    article {
      padding: 1.5rem;
    }
    
    article h2 {
      font-size: 1.5rem;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
  }

  /* Animations */
  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
  }

  .floating {
    animation: float 3s ease-in-out infinite;
  }

  /* Particle effect */
  .particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
  }

  .particle {
    position: absolute;
    background: rgba(255,255,255,0.6);
    border-radius: 50%;
    animation: moveParticles linear infinite;
  }

  @keyframes moveParticles {
    0% {
      transform: translateY(0) translateX(0);
      opacity: 0;
    }
    10% {
      opacity: 1;
    }
    90% {
      opacity: 1;
    }
    100% {
      transform: translateY(-100vh) translateX(100px);
      opacity: 0;
    }
  }