:root {
    --primary: #0d47a1;
    --secondary: #6a1b9a;
    --accent: #ffeb3b;
    --light: #c5cae9;
    --dark: #0a1f44;
    --text: #e0e0e0;
    --bg-gradient: linear-gradient(135deg, var(--primary), var(--secondary), var(--light));
  }

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

  body {
    background: var(--bg-gradient);
    color: var(--text);
    line-height: 1.8;
    overflow-x: hidden;
  }

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

  .header {
    text-align: center;
    padding: 60px 0;
    position: relative;
  }

  .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: -1;
  }

  h1, h2, h3, h4 {
    font-weight: 300;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  }

  h1 {
    font-size: 3rem;
    background: linear-gradient(90deg, var(--light), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  h2 {
    font-size: 2.2rem;
    border-left: 4px solid var(--accent);
    padding-left: 15px;
    margin: 40px 0 20px;
  }

  h3 {
    font-size: 1.8rem;
    margin: 30px 0 15px;
  }

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

  .note {
    background: rgba(255,255,255,0.1);
    padding: 20px;
    border-radius: 8px;
    margin: 30px 0;
    border-left: 4px solid var(--accent);
  }

  pre {
    background: rgba(0,0,0,0.3);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    overflow: auto;
    border: 1px solid rgba(255,255,255,0.1);
  }

  code {
    font-family: 'Courier New', monospace;
    color: var(--accent);
    background: transparent;
  }

  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: rgba(255,255,255,0.05);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.3);
  }

  .img-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin: 40px 0;
    justify-content: center;
  }

  .img-box {
    width: 320px;
    height: 320px;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
    transition: transform 0.3s;
  }

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

  .img-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
  }

  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(13, 71, 161, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    z-index: 1000;
    display: flex;
    justify-content: center;
  }

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

  .nav-links a {
    color: white;
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.3s;
    position: relative;
  }

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

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

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

  .content {
    padding-top: 80px;
  }

  .footer {
    text-align: center;
    padding: 40px 0;
    margin-top: 60px;
    background: rgba(0,0,0,0.2);
  }

  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
  }

  .floating {
    animation: float 6s ease-in-out infinite;
  }

  @media (max-width: 768px) {
    .grid {
      grid-template-columns: 1fr;
    }
    
    .nav-links {
      gap: 15px;
    }
    
    h1 {
      font-size: 2.2rem;
    }
    
    h2 {
      font-size: 1.8rem;
    }
  }