:root {
    --primary: #0d47a1;
    --secondary: #546e7a;
    --accent: #ff9800;
    --light: #f5f5f5;
    --dark: #212121;
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    min-height: 100%;
    padding-top: 80px;
  }

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

  .header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(13, 71, 161, 0.95);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(8px);
    z-index: 1000;
    padding: 15px 0;
  }

  .header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
  }

  .logo-icon {
    margin-right: 10px;
    width: 30px;
    height: 30px;
    background: var(--accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .nav {
    display: flex;
    gap: 20px;
  }

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

  .nav-link:hover {
    background: var(--accent);
    transform: translateY(-2px);
  }

  .nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
  }

  .nav-link:hover::after {
    width: 60%;
  }

  .hero {
    padding: 80px 0;
    text-align: center;
    background: linear-gradient(135deg, rgba(13, 71, 161, 0.1) 0%, rgba(84, 110, 122, 0.1) 100%);
    border-radius: 0 0 30px 30px;
    margin-bottom: 50px;
    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') no-repeat center/cover;
    opacity: 0.1;
    z-index: -1;
  }

  .hero-title {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--primary);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    animation: fadeIn 1s ease;
  }

  .hero-subtitle {
    font-size: 1.2rem;
    color: var(--secondary);
    max-width: 700px;
    margin: 0 auto 30px;
  }

  .notice {
    background: var(--accent);
    color: white;
    padding: 15px;
    border-radius: 10px;
    margin: 20px 0;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  }

  .content-section {
    padding: 50px 0;
  }

  .section-title {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 30px;
    position: relative;
    display: inline-block;
  }

  .section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
  }

  article {
    background: white;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    margin-bottom: 50px;
  }

  article h2 {
    font-size: 1.8rem;
    color: var(--primary);
    margin: 30px 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #eee;
  }

  article h3 {
    font-size: 1.5rem;
    color: var(--secondary);
    margin: 25px 0 15px;
  }

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

  pre {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    border-left: 4px solid var(--accent);
    font-family: 'Courier New', monospace;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.05);
  }

  code {
    background: #f8f9fa;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: #d63384;
  }

  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
  }

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
  }

  .gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
  }

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

  .gallery-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 15px;
    transform: translateY(100%);
    transition: transform 0.3s ease;
  }

  .gallery-item:hover .gallery-caption {
    transform: translateY(0);
  }

  .footer {
    background: var(--dark);
    color: white;
    padding: 50px 0 20px;
    text-align: center;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
  }

  .footer-link {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
  }

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

  .footer-copyright {
    opacity: 0.7;
    font-size: 0.9rem;
  }

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

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

    .nav {
      margin-top: 20px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .hero-title {
      font-size: 2.2rem;
    }

    article {
      padding: 30px 20px;
    }

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