:root {
    --primary: #0D47A1;
    --secondary: #42A5F5;
    --accent: #00E676;
    --dark: #121212;
    --light: #F5F5F5;
    --text: #333;
    --white: #fff;
  }

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

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

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

  .header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: linear-gradient(135deg, var(--primary), var(--dark));
    color: var(--white);
    padding: 20px 0;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
  }

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

  .logo {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  }

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

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

  .nav-link:hover {
    background-color: rgba(255,255,255,0.1);
  }

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

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

  .progress-container {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    height: 5px;
    background-color: rgba(0,0,0,0.1);
    z-index: 999;
  }

  .progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--secondary));
    width: 0;
    transition: width 0.1s ease-out;
  }

  .hero {
    height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(rgba(13, 71, 161, 0.7), rgba(13, 71, 161, 0.7)), 
                url('https://images.gptkong.com/demo/sample1.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: var(--white);
    text-align: center;
    margin-top: 70px;
    position: relative;
    overflow: hidden;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 50%, transparent 0%, rgba(0,0,0,0.5) 100%);
    z-index: 1;
  }

  .hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 0 20px;
  }

  .hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.5);
    animation: fadeInDown 1s ease-out;
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0;
    animation: fadeIn 1s ease-out 0.5s forwards;
  }

  .cta-button {
    display: inline-block;
    background: linear-gradient(45deg, var(--accent), var(--secondary));
    color: var(--white);
    padding: 15px 40px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    box-shadow: 0 5px 15px rgba(0, 230, 118, 0.4);
    transition: all 0.3s ease;
    transform: translateY(20px);
    opacity: 0;
    animation: fadeInUp 1s ease-out 1s forwards;
  }

  .cta-button:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 8px 25px rgba(0, 230, 118, 0.6);
  }

  .notice {
    background-color: var(--primary);
    color: var(--white);
    padding: 15px;
    text-align: center;
    font-size: 0.9rem;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
  }

  .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: 3px;
    background: linear-gradient(90deg, var(--accent), var(--secondary));
  }

  .grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
  }

  .card {
    background-color: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    position: relative;
  }

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

  .card-img {
    height: 200px;
    overflow: hidden;
  }

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

  .card:hover .card-img img {
    transform: scale(1.1);
  }

  .card-content {
    padding: 25px;
  }

  .card h3 {
    color: var(--primary);
    margin-bottom: 15px;
    font-size: 1.4rem;
  }

  .card p {
    color: var(--text);
    margin-bottom: 20px;
  }

  .read-more {
    display: inline-block;
    color: var(--secondary);
    font-weight: 600;
    text-decoration: none;
    position: relative;
    padding-bottom: 5px;
  }

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

  .read-more:hover::after {
    width: 100%;
  }

  .parallax-section {
    height: 500px;
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 60px 0;
  }

  .parallax-content {
    background-color: rgba(13, 71, 161, 0.8);
    color: var(--white);
    padding: 40px;
    max-width: 800px;
    text-align: center;
    border-radius: 10px;
  }

  .code-container {
    background-color: var(--dark);
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    overflow: hidden;
    position: relative;
  }

  .code-container pre {
    margin: 0;
    overflow-x: auto;
  }

  .code-container code {
    font-family: 'Courier New', monospace;
    color: var(--accent);
    font-size: 14px;
    line-height: 1.5;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  }

  th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
  }

  th {
    background-color: var(--primary);
    color: var(--white);
    font-weight: 500;
  }

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

  .footer {
    background-color: var(--dark);
    color: var(--white);
    padding: 60px 0 30px;
  }

  .footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
  }

  .footer-column h3 {
    color: var(--accent);
    margin-bottom: 20px;
    font-size: 1.2rem;
  }

  .footer-links {
    list-style: none;
  }

  .footer-links li {
    margin-bottom: 10px;
  }

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

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

  .copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
  }

  @keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
  }

  @keyframes fadeInDown {
    from {
      opacity: 0;
      transform: translateY(-30px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  @keyframes fadeInUp {
    from {
      opacity: 0;
      transform: translateY(30px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.5rem;
    }
    
    .nav {
      display: none;
    }
    
    .grid-container {
      grid-template-columns: 1fr;
    }
    
    .section {
      padding: 60px 0;
    }
  }