:root {
    --primary: #1E3A8A;
    --secondary: #6366F1;
    --accent: #34D399;
    --highlight: #F59E0B;
    --light: #FFFFFF;
    --gray: #F3F4F6;
    --dark: #111827;
  }

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

  body {
    background: var(--gray);
    color: var(--dark);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
  }

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

  .header {
    position: relative;
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--light);
    clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
    margin-bottom: 80px;
  }

  .header::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: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    padding: 0 20px;
  }

  .header h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 4px 8px rgba(0,0,0,0.2);
  }

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

  .notice {
    background: var(--light);
    color: var(--primary);
    padding: 15px 20px;
    border-radius: 8px;
    display: inline-block;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    margin-top: 30px;
    font-weight: bold;
  }

  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(30, 58, 138, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    z-index: 1000;
    transition: all 0.3s ease;
  }

  .navbar.scrolled {
    background: rgba(30, 58, 138, 0.95);
    padding: 10px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  }

  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

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

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

  .nav-item {
    margin-left: 30px;
  }

  .nav-link {
    color: var(--light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
  }

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

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

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

  .section {
    padding: 80px 0;
    position: relative;
  }

  .section-title {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
  }

  .section-title h2 {
    font-size: 2.5rem;
    color: var(--primary);
    display: inline-block;
    padding-bottom: 15px;
  }

  .section-title h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent), var(--highlight));
    border-radius: 2px;
  }

  .article-container {
    background: var(--light);
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    padding: 50px;
    margin-bottom: 80px;
  }

  article h2 {
    color: var(--primary);
    margin: 40px 0 20px;
    font-size: 1.8rem;
    position: relative;
    padding-bottom: 10px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--accent);
  }

  article h3 {
    color: var(--secondary);
    margin: 30px 0 15px;
    font-size: 1.4rem;
  }

  article p {
    margin-bottom: 20px;
    line-height: 1.8;
  }

  article strong {
    color: var(--primary);
  }

  pre {
    background: #2d3748;
    color: #f7fafc;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 25px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    position: relative;
  }

  pre::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--accent), var(--highlight));
    border-radius: 8px 0 0 8px;
  }

  code {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
  }

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

  .image-card {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .image-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
  }

  .image-card img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    transition: transform 0.5s ease;
  }

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

  .image-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
    padding: 20px;
    color: var(--light);
  }

  .footer {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--light);
    padding: 60px 0 30px;
    text-align: center;
    clip-path: polygon(0 15%, 100% 0, 100% 100%, 0 100%);
    margin-top: 80px;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .footer p {
    margin-bottom: 20px;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    list-style: none;
    margin: 30px 0;
  }

  .footer-link {
    margin: 0 15px;
  }

  .footer-link a {
    color: var(--light);
    text-decoration: none;
    transition: color 0.3s ease;
  }

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

  @media (max-width: 768px) {
    .header {
      height: 500px;
    }

    .header h1 {
      font-size: 2.2rem;
    }

    .nav-menu {
      display: none;
    }

    .article-container {
      padding: 30px;
    }

    .section-title h2 {
      font-size: 2rem;
    }

    article h2 {
      font-size: 1.5rem;
    }
  }

  @media (max-width: 480px) {
    .header {
      height: 400px;
      clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
    }

    .header h1 {
      font-size: 1.8rem;
    }

    .article-container {
      padding: 20px;
    }

    .image-grid {
      grid-template-columns: 1fr;
    }
  }

  /* 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; }