@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&display=swap');
  
  :root {
    --primary: #121212;
    --secondary: #1e1e1e;
    --accent: #00aaff;
    --highlight: #00ffff;
    --text: #e0e0e0;
    --card-bg: #2c2c2c;
    --border: #3a3a3a;
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    background: radial-gradient(circle at center, var(--primary), var(--secondary);
    color: var(--text);
    font-family: 'Roboto', sans-serif;
    font-size: 17px;
    line-height: 1.7;
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }
  
  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
  }
  
  .header {
    text-align: center;
    padding: 60px 0 40px;
    position: relative;
  }
  
  .header::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
  }
  
  h1, h2, h3, h4 {
    font-weight: 500;
    margin-bottom: 1.2em;
    color: var(--highlight);
  }
  
  h1 {
    font-size: 2.5rem;
    letter-spacing: 1px;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.3);
  }
  
  h2 {
    font-size: 1.8rem;
    margin-top: 2.5rem;
    position: relative;
    padding-bottom: 10px;
  }
  
  h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 2px;
    background: var(--accent);
  }
  
  h3 {
    font-size: 1.4rem;
    margin-top: 2rem;
  }
  
  p {
    margin-bottom: 1.5em;
  }
  
  strong {
    color: var(--highlight);
  }
  
  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }
  
  .card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 30px;
    transition: all 0.3s ease;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
  }
  
  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3),
                0 0 15px rgba(0, 255, 255, 0.3);
  }
  
  .img-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin: 40px 0;
  }
  
  .decor-img {
    width: 150px;
    height: 150px;
    object-fit: cover;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    filter: grayscale(30%);
  }
  
  .decor-img:hover {
    transform: scale(1.05);
    filter: grayscale(0%);
    box-shadow: 0 8px 20px rgba(0, 255, 255, 0.4);
  }
  
  pre {
    background: #1a1a1a;
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    border-left: 4px solid var(--accent);
  }
  
  code {
    font-family: 'Roboto Mono', monospace;
    color: #f8f8f2;
    font-size: 0.9em;
  }
  
  .language-css {
    color: #66d9ef;
  }
  
  .language-html {
    color: #f92672;
  }
  
  .language-javascript {
    color: #a6e22e;
  }
  
  ol, ul {
    margin-left: 30px;
    margin-bottom: 1.5em;
  }
  
  li {
    margin-bottom: 0.8em;
  }
  
  .notice {
    background: rgba(0, 170, 255, 0.1);
    border-left: 4px solid var(--accent);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
  }
  
  .nav-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin: 40px 0;
  }
  
  .nav-link {
    color: var(--text);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 6px;
    background: rgba(0, 170, 255, 0.1);
    transition: all 0.3s ease;
  }
  
  .nav-link:hover {
    background: rgba(0, 170, 255, 0.3);
    color: var(--highlight);
  }
  
  @media (max-width: 768px) {
    body {
      font-size: 16px;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.5rem;
    }
    
    .grid {
      grid-template-columns: 1fr;
    }
    
    .decor-img {
      width: 120px;
      height: 120px;
    }
  }
  
  @keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(0, 255, 255, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(0, 255, 255, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 255, 255, 0); }
  }
  
  .pulse {
    animation: pulse 2s infinite;
  }