:root {
    --primary: #0f2027;
    --secondary: #203a43;
    --accent: #0ef;
    --text: #e0e0e0;
    --card-bg: rgba(255, 255, 255, 0.1);
    --nav-bg: rgba(0, 0, 0, 0.7);
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, var(--primary), var(--secondary), #2c5364);
    background-size: 400% 400%;
    animation: gradientAnimation 15s ease infinite;
    min-height: 100%;
    padding-top: 80px;
  }

  @keyframes gradientAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }

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

  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--nav-bg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    backdrop-filter: blur(10px);
  }

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

  .navbar-links {
    display: flex;
    gap: 30px;
  }

  .navbar a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
  }

  .navbar a:hover {
    color: var(--accent);
  }

  .navbar a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: var(--accent);
    transition: width 0.3s ease;
  }

  .navbar a:hover::after {
    width: 100%;
  }

  .hero {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 100px 20px;
    position: relative;
    overflow: hidden;
  }

  .hero::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: 0.2;
    z-index: -1;
  }

  .hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    color: white;
    text-shadow: 0 0 10px rgba(14, 242, 14, 0.5);
    animation: fadeIn 1s ease-in-out;
  }

  .hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin-bottom: 40px;
    animation: fadeIn 1.5s ease-in-out;
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .notice {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px;
    border-radius: 8px;
    margin: 30px auto;
    max-width: 800px;
    text-align: center;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.2);
  }

  .content-section {
    padding: 60px 0;
  }

  article {
    background: rgba(0, 0, 0, 0.5);
    padding: 40px;
    border-radius: 15px;
    margin: 30px auto;
    max-width: 900px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
  }

  article h2 {
    color: var(--accent);
    margin: 30px 0 20px;
    font-size: 2rem;
    position: relative;
    padding-bottom: 10px;
  }

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

  article h3 {
    color: #7fdbff;
    margin: 25px 0 15px;
    font-size: 1.5rem;
  }

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

  pre {
    background: rgba(0, 0, 0, 0.3);
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 25px 0;
    border-left: 4px solid var(--accent);
    font-family: 'Courier New', monospace;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent);
    color: black;
    padding: 2px 10px;
    font-size: 0.8rem;
    border-bottom-left-radius: 5px;
  }

  code {
    font-family: 'Courier New', monospace;
    color: #7fdbff;
  }

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .image-card {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
  }

  .image-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(14, 242, 14, 0.2);
  }

  .image-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    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(to bottom, transparent 60%, rgba(0, 0, 0, 0.7));
  }

  .card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 30px;
    margin: 30px 0;
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.18);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.5);
  }

  .fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  }

  .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
  }

  footer {
    text-align: center;
    padding: 30px;
    margin-top: 60px;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(5px);
  }

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

  @media (max-width: 480px) {
    .navbar-links {
      display: none;
    }
    
    .hero h1 {
      font-size: 2rem;
    }
    
    article h2 {
      font-size: 1.5rem;
    }
  }