:root {
    --primary: #0d47a1;
    --secondary: #1e88e5;
    --accent: #00e676;
    --dark: #121212;
    --light: #f5f5f5;
    --neon: #00ff9d;
    --electric: #2979ff;
  }

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

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&display=swap');
  }

  body {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, var(--dark), #1a237e);
    color: var(--light);
    line-height: 1.6;
    overflow-x: hidden;
    animation: fadeIn 1.5s ease;
  }

  @keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
  }

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

  header {
    position: relative;
    height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
  }

  .header-content {
    position: relative;
    z-index: 2;
    padding: 2rem;
    background: rgba(18, 18, 18, 0.7);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    max-width: 800px;
    margin: 0 auto;
  }

  .header-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    opacity: 0.3;
    z-index: 1;
  }

  h1, h2, h3, h4 {
    font-weight: 500;
    margin-bottom: 1.5rem;
    line-height: 1.3;
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, var(--electric), var(--neon));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 1rem;
  }

  h2 {
    font-size: 1.8rem;
    color: var(--neon);
    border-bottom: 2px solid var(--secondary);
    padding-bottom: 0.5rem;
    display: inline-block;
  }

  h3 {
    font-size: 1.5rem;
    color: var(--electric);
  }

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

  .grid-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
  }

  .card {
    background: rgba(30, 30, 30, 0.7);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 150, 255, 0.2);
  }

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
  }

  .image-card {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
    position: relative;
  }

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

  .image-card img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
  }

  .image-card:hover img {
    transform: scale(1.1);
  }

  .image-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(41, 121, 255, 0.3), rgba(0, 255, 157, 0.3));
    opacity: 0;
    transition: opacity 0.3s ease;
  }

  .image-card:hover::after {
    opacity: 1;
  }

  pre {
    background: rgba(20, 20, 20, 0.9);
    border-radius: 8px;
    padding: 1.5rem;
    overflow-x: auto;
    margin: 2rem 0;
    border-left: 4px solid var(--neon);
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
  }

  code {
    font-family: 'Roboto Mono', monospace;
    color: var(--neon);
    font-size: 0.9rem;
  }

  .language-css {
    color: #80deea;
  }

  ol, ul {
    margin-left: 2rem;
    margin-bottom: 1.5rem;
  }

  li {
    margin-bottom: 0.5rem;
  }

  .floating-notice {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(18, 18, 18, 0.9);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    border: 1px solid var(--neon);
    z-index: 100;
    animation: pulse 2s infinite;
  }

  @keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(0, 255, 157, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(0, 255, 157, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 255, 157, 0); }
  }

  .nav-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 2rem 0;
    flex-wrap: wrap;
  }

  .nav-link {
    color: var(--light);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    background: rgba(41, 121, 255, 0.2);
    border: 1px solid var(--electric);
    transition: all 0.3s ease;
  }

  .nav-link:hover {
    background: rgba(41, 121, 255, 0.5);
    transform: translateY(-2px);
  }

  .particle {
    position: absolute;
    background: var(--neon);
    border-radius: 50%;
    opacity: 0.5;
    animation: float 15s infinite linear;
  }

  @keyframes float {
    0% { transform: translateY(0) translateX(0); opacity: 0; }
    10% { opacity: 0.5; }
    90% { opacity: 0.5; }
    100% { transform: translateY(-100vh) translateX(100px); opacity: 0; }
  }

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