:root {
    --primary: rgba(0, 123, 255, 0.8);
    --secondary: rgba(108, 117, 125, 0.8);
    --accent: rgba(255, 193, 7, 0.9);
    --text: #f8f9fa;
    --bg: #121a25;
    --card-bg: rgba(255, 255, 255, 0.1);
  }

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

  body {
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100%;
    padding-top: 80px;
  }

  .notice {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--accent);
    color: #121a25;
    padding: 10px 20px;
    border-radius: 50px;
    font-weight: bold;
    z-index: 1000;
    box-shadow: 0 4px 15px rgba(255, 193, 7, 0.3);
  }

  .hero {
    height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    position: relative;
    overflow: hidden;
    margin-bottom: 80px;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover;
    opacity: 0.2;
    z-index: -1;
  }

  .hero-content {
    text-align: center;
    max-width: 800px;
    padding: 0 20px;
    z-index: 2;
  }

  .hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
  }

  .particle-background {
    position: absolute;
    width: 100%;
    height: 100%;
    background: transparent;
    overflow: hidden;
    z-index: -1;
  }

  .particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 50%;
    animation: move 10s linear infinite;
  }

  @keyframes move {
    from { transform: translateY(0) translateX(0); }
    to { transform: translateY(-1000px) translateX(1000px); }
  }

  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(10px);
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.2);
  }

  .navbar-logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text);
    text-decoration: none;
  }

  .navbar-nav {
    display: flex;
    gap: 30px;
    list-style: none;
  }

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

  .nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-3px);
  }

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

  article {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(15px);
    border-radius: 15px;
    padding: 40px;
    margin-bottom: 60px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  }

  article h2 {
    font-size: 2.2rem;
    margin-bottom: 30px;
    color: var(--accent);
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), transparent);
  }

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

  article p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    line-height: 1.8;
  }

  pre {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    border-left: 4px solid var(--accent);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #f8f9fa;
  }

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

  .card {
    background: var(--card-bg);
    backdrop-filter: blur(15px);
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.25);
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
  }

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

  .card h4 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--accent);
  }

  .card p {
    margin-bottom: 15px;
    opacity: 0.9;
  }

  .features {
    list-style: none;
  }

  .features li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 10px;
  }

  .features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: bold;
  }

  .button {
    display: inline-block;
    background: linear-gradient(45deg, var(--primary), var(--secondary));
    color: var(--text);
    padding: 12px 25px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 500;
    margin-top: 15px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.3);
  }

  .button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 123, 255, 0.4);
  }

  footer {
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    padding: 30px 0;
    text-align: center;
    margin-top: 80px;
  }

  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.5rem;
    }
    
    .navbar-nav {
      gap: 15px;
    }
    
    article {
      padding: 30px 20px;
    }
  }

  @media (max-width: 480px) {
    .hero {
      height: 70vh;
    }
    
    .hero h1 {
      font-size: 2rem;
    }
    
    .navbar {
      flex-direction: column;
      padding: 15px;
    }
    
    .navbar-nav {
      margin-top: 15px;
      flex-wrap: wrap;
      justify-content: center;
    }
    
    article h2 {
      font-size: 1.8rem;
    }
    
    article h3 {
      font-size: 1.5rem;
    }
  }