:root {
    --primary: #1E3C72;
    --secondary: #2A5298;
    --accent: #FF512F;
    --text: #f8f9fa;
    --card-bg: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s ease;
  }

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

  body {
    font-family: 'Open Sans', sans-serif;
    color: var(--text);
    line-height: 1.6;
    background: linear-gradient(135deg, var(--primary), var(--secondary), #6A3093);
    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;
    left: 0;
    width: 100%;
    background: rgba(30, 60, 114, 0.9);
    backdrop-filter: blur(10px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    z-index: 1000;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  }

  .navbar-brand {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
    letter-spacing: 1px;
  }

  .navbar-nav {
    display: flex;
    list-style: none;
    gap: 30px;
  }

  .nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: var(--transition);
  }

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

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

  .hero {
    padding: 100px 0;
    text-align: center;
    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 center;
    background-size: cover;
    opacity: 0.1;
    z-index: -1;
  }

  .hero h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 3rem;
    margin-bottom: 20px;
    background: linear-gradient(90deg, #fff, #FF512F);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
  }

  .hero p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 40px;
  }

  .notice {
    background: rgba(255,255,255,0.2);
    padding: 15px;
    border-radius: 10px;
    margin: 20px 0;
    text-align: center;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255,255,255,0.1);
  }

  article {
    background: rgba(30, 60, 114, 0.7);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    margin: 40px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  }

  article h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2rem;
    margin-bottom: 30px;
    color: white;
    position: relative;
    padding-bottom: 15px;
  }

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

  article h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.5rem;
    margin: 30px 0 20px;
    color: white;
  }

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

  article color {
    color: var(--accent);
    font-weight: bold;
  }

  pre {
    background: rgba(0,0,0,0.3);
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    border-left: 4px solid var(--accent);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #f8f9fa;
  }

  .language-css {
    display: block;
    white-space: pre;
  }

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

  .gallery-item {
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transition: var(--transition);
    position: relative;
  }

  .gallery-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.3);
  }

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

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

  .gallery-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(0,0,0,0.7), transparent);
    opacity: 0;
    transition: var(--transition);
  }

  .gallery-item:hover::after {
    opacity: 1;
  }

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

  .card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.1);
    transition: var(--transition);
  }

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

  .card h4 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: white;
  }

  .footer {
    background: rgba(30, 60, 114, 0.9);
    padding: 40px 0;
    margin-top: 80px;
    text-align: center;
  }

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

  .social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
  }

  .social-link {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
  }

  .social-link:hover {
    background: var(--accent);
    transform: translateY(-5px);
  }

  @media (max-width: 768px) {
    .navbar {
      padding: 15px 20px;
    }
    
    .navbar-nav {
      gap: 15px;
    }
    
    .hero h1 {
      font-size: 2rem;
    }
    
    article {
      padding: 30px 20px;
    }
    
    .card-container {
      grid-template-columns: 1fr;
    }
  }