:root {
    --primary: #03A9F4;
    --secondary: #FFC107;
    --dark: #333;
    --light: #f8f9fa;
    --gray: #6c757d;
    --white: #fff;
    --transition: all 0.3s ease;
  }

  @import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&family=Lato:wght@400;700&display=swap');

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

  body {
    font-family: 'Lato', sans-serif;
    color: var(--dark);
    line-height: 1.6;
    background-color: var(--light);
    overflow-x: hidden;
  }

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

  /* Header */
  .header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
  }

  .logo {
    font-family: 'Roboto', sans-serif;
    font-weight: 700;
    font-size: 24px;
    color: var(--primary);
    text-decoration: none;
  }

  .nav-links {
    display: flex;
    list-style: none;
  }

  .nav-links li {
    margin-left: 30px;
  }

  .nav-links a {
    color: var(--dark);
    text-decoration: none;
    font-family: 'Roboto', sans-serif;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
  }

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

  .nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
  }

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

  /* Hero Section */
  .hero {
    height: 600px;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, rgba(3, 169, 244, 0.1), rgba(255, 193, 7, 0.1));
    position: relative;
    overflow: hidden;
    margin-top: 80px;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
    background-size: contain;
    opacity: 0.2;
    z-index: -1;
  }

  .hero-content {
    max-width: 600px;
  }

  .hero h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--primary);
    line-height: 1.2;
  }

  .hero p {
    font-size: 18px;
    margin-bottom: 30px;
    color: var(--gray);
  }

  .notice {
    background: var(--secondary);
    color: var(--dark);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 30px;
    font-weight: 500;
    text-align: center;
  }

  /* Main Content */
  .main-content {
    padding: 80px 0;
  }

  article {
    background: var(--white);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    margin-bottom: 40px;
  }

  article h2 {
    font-size: 32px;
    color: var(--primary);
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--secondary);
  }

  article h3 {
    font-size: 24px;
    color: var(--primary);
    margin: 30px 0 20px;
  }

  article p {
    margin-bottom: 20px;
    font-size: 17px;
  }

  /* Code Blocks */
  pre {
    background: #282c34;
    color: #abb2bf;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 20px 0;
    font-family: 'Courier New', Courier, monospace;
    font-size: 15px;
    line-height: 1.5;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  }

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

  /* Tables */
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  }

  th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
  }

  th {
    background-color: var(--primary);
    color: var(--white);
    font-weight: 500;
  }

  tr:nth-child(even) {
    background-color: #f2f2f2;
  }

  tr:hover {
    background-color: rgba(3, 169, 244, 0.1);
  }

  /* Gallery */
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
  }

  .gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: var(--transition);
  }

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

  /* Buttons */
  .btn {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-family: 'Roboto', sans-serif;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  }

  .btn:hover {
    background: #0288d1;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
  }

  .btn-secondary {
    background: var(--secondary);
    color: var(--dark);
  }

  .btn-secondary:hover {
    background: #ffb300;
  }

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

  .fade-in {
    animation: fadeIn 0.8s ease forwards;
  }

  .delay-1 { animation-delay: 0.2s; }
  .delay-2 { animation-delay: 0.4s; }
  .delay-3 { animation-delay: 0.6s; }

  /* Footer */
  .footer {
    background: var(--dark);
    color: var(--white);
    padding: 60px 0 30px;
    text-align: center;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    list-style: none;
    margin-bottom: 30px;
  }

  .footer-links li {
    margin: 0 15px;
  }

  .footer-links a {
    color: var(--white);
    text-decoration: none;
    transition: var(--transition);
  }

  .footer-links a:hover {
    color: var(--secondary);
  }

  .copyright {
    margin-top: 30px;
    color: var(--gray);
    font-size: 14px;
  }

  /* Responsive */
  @media (max-width: 992px) {
    .hero h1 {
      font-size: 36px;
    }
  }

  @media (max-width: 768px) {
    .navbar {
      flex-direction: column;
    }

    .nav-links {
      margin-top: 20px;
    }

    .nav-links li {
      margin: 0 10px;
    }

    .hero {
      height: auto;
      padding: 100px 0;
    }

    .hero-content {
      text-align: center;
    }

    .gallery {
      grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
  }

  @media (max-width: 576px) {
    .hero h1 {
      font-size: 28px;
    }

    article {
      padding: 20px;
    }

    article h2 {
      font-size: 26px;
    }

    article h3 {
      font-size: 22px;
    }
  }