:root {
    --primary: #1A237E;
    --secondary: #00E676;
    --accent: #FFB300;
    --bg-dark: #121212;
    --text-light: #FFFFFF;
    --text-muted: rgba(255,255,255,0.7);
  }

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

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

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

  /* Header Styles */
  .header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 0;
    background: rgba(18, 18, 18, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all 0.5s ease;
  }

  .header.scrolled {
    background: rgba(18, 18, 18, 0.95);
    box-shadow: 0 5px 20px rgba(0,0,0,0.3);
  }

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

  .logo {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--secondary);
    text-decoration: none;
  }

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

  .nav-link {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 600;
    position: relative;
    transition: color 0.3s ease;
  }

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

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

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

  /* Hero Section */
  .hero {
    height: 80vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--primary), var(--bg-dark));
    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') center/cover no-repeat;
    opacity: 0.1;
    z-index: 0;
  }

  .hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
  }

  .hero-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    background: linear-gradient(45deg, var(--secondary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 3px 3px 15px rgba(0,0,0,0.3);
  }

  .hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 30px;
    max-width: 600px;
  }

  .scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
  }

  @keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
      transform: translateY(0) translateX(-50%);
    }
    40% {
      transform: translateY(-20px) translateX(-50%);
    }
    60% {
      transform: translateY(-10px) translateX(-50%);
    }
  }

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

  section {
    margin-bottom: 80px;
    position: relative;
  }

  section::before {
    content: '';
    position: absolute;
    top: -40px;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--secondary), transparent);
  }

  h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.2rem;
    margin-bottom: 30px;
    color: var(--secondary);
    position: relative;
    display: inline-block;
  }

  h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 50%;
    height: 3px;
    background: var(--accent);
  }

  p {
    font-size: 1.1rem;
    margin-bottom: 20px;
    color: var(--text-muted);
  }

  .highlight {
    color: var(--secondary);
    font-weight: 600;
  }

  /* Code Blocks */
  pre {
    background: rgba(0,0,0,0.3);
    border-left: 4px solid var(--secondary);
    padding: 20px;
    border-radius: 5px;
    margin: 30px 0;
    overflow-x: auto;
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    color: var(--secondary);
    font-size: 0.9rem;
  }

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

  .image-card {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .image-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.3);
  }

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

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

  /* Table Styles */
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    background: rgba(0,0,0,0.2);
    border-radius: 10px;
    overflow: hidden;
  }

  th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }

  th {
    background: var(--primary);
    color: var(--text-light);
    font-weight: 600;
  }

  tr:hover {
    background: rgba(0,230,118,0.1);
  }

  /* Footer */
  .footer {
    background: linear-gradient(to top, var(--primary), var(--bg-dark));
    padding: 50px 0 20px;
    text-align: center;
  }

  .footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
  }

  .reference {
    background: rgba(255,179,0,0.1);
    padding: 15px;
    border-radius: 5px;
    margin: 40px 0;
    border-left: 3px solid var(--accent);
  }

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

  .animate {
    animation: fadeIn 1s ease-out forwards;
  }

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

  /* Responsive */
  @media (max-width: 768px) {
    .hero-title {
      font-size: 2.5rem;
    }

    .nav-links {
      display: none;
    }

    .hamburger {
      display: block;
      cursor: pointer;
    }

    section {
      margin-bottom: 60px;
    }

    h2 {
      font-size: 1.8rem;
    }
  }