:root {
    --primary: #03A9F4;
    --secondary: #8BC34A;
    --accent: #FFC107;
    --dark: #1A237E;
    --light: #E3F2FD;
    --text: #212121;
    --gray: #757575;
  }

  @font-face {
    font-family: 'Poppins Bold';
    src: local('Poppins Bold'), local('Poppins-Bold');
  }

  @font-face {
    font-family: 'Roboto Regular';
    src: local('Roboto Regular'), local('Roboto-Regular');
  }

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

  body {
    font-family: 'Roboto Regular', sans-serif;
    color: var(--text);
    background: linear-gradient(135deg, var(--light) 0%, #f9f9f9 100%);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  .header {
    position: relative;
    height: 80vh;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(rgba(26, 35, 126, 0.7), rgba(3, 169, 244, 0.7)), 
                url('https://images.gptkong.com/demo/sample1.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: white;
    text-align: center;
    clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
    margin-bottom: 60px;
  }

  .header-content {
    max-width: 800px;
    padding: 0 20px;
    animation: fadeInUp 1s ease-out;
  }

  .header h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
    font-family: 'Poppins Bold', sans-serif;
  }

  .header p {
    font-size: 1.2rem;
    margin-bottom: 30px;
  }

  .notice {
    background: var(--accent);
    color: var(--dark);
    padding: 15px;
    text-align: center;
    font-weight: bold;
    margin-bottom: 40px;
    border-radius: 0 0 8px 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  }

  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(26, 35, 126, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    z-index: 1000;
    display: flex;
    justify-content: center;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
  }

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

  .nav-links a {
    color: white;
    text-decoration: none;
    font-family: 'Poppins Bold', sans-serif;
    font-size: 1rem;
    position: relative;
    padding: 5px 0;
    transition: all 0.3s ease;
  }

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

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

  .nav-links a:hover::after {
    width: 100%;
  }

  article {
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    padding: 50px;
    margin-bottom: 60px;
    position: relative;
    overflow: hidden;
  }

  article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary), var(--secondary));
  }

  h2, h3, h4 {
    font-family: 'Poppins Bold', sans-serif;
    margin: 30px 0 20px;
    color: var(--dark);
  }

  h2 {
    font-size: 2.2rem;
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(to right, var(--primary), var(--accent));
  }

  h3 {
    font-size: 1.8rem;
  }

  h4 {
    font-size: 1.4rem;
  }

  p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    line-height: 1.7;
  }

  .img-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin: 30px 0;
  }

  .img-box {
    flex: 1 1 300px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .img-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 25px rgba(0,0,0,0.15);
  }

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

  .img-box:hover img {
    transform: scale(1.05);
  }

  pre {
    background: #f5f7fa;
    border-left: 4px solid var(--primary);
    border-radius: 0 8px 8px 0;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.5;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--primary);
    color: white;
    padding: 3px 10px;
    font-size: 0.8rem;
    border-radius: 0 0 0 4px;
  }

  code {
    font-family: 'Courier New', monospace;
    background: rgba(3, 169, 244, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.95rem;
  }

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

  .card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border-top: 4px solid var(--primary);
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
  }

  .card h3 {
    margin-top: 0;
    color: var(--primary);
  }

  .footer {
    background: linear-gradient(135deg, var(--dark), #0D47A1);
    color: white;
    padding: 50px 0;
    text-align: center;
    clip-path: polygon(0 20%, 100% 0, 100% 100%, 0 100%);
    margin-top: 80px;
  }

  .footer p {
    max-width: 600px;
    margin: 0 auto 20px;
  }

  @keyframes fadeInUp {
    from {
      opacity: 0;
      transform: translateY(30px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2.5rem;
    }
    
    .header p {
      font-size: 1rem;
    }
    
    .nav-links {
      gap: 15px;
    }
    
    article {
      padding: 30px 20px;
    }
    
    .grid-section {
      grid-template-columns: 1fr;
    }
  }