:root {
    --primary: #0f2027;
    --secondary: #203a43;
    --accent: #00c6ff;
    --highlight: #00ff9d;
    --text: #ffffff;
    --card-bg: rgba(255, 255, 255, 0.1);
  }

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

  body {
    background: linear-gradient(135deg, var(--primary), var(--secondary), #2c5364);
    color: var(--text);
    font-family: 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    padding: 0;
    overflow-x: hidden;
  }

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

  .hero {
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: radial-gradient(circle at center, rgba(0,198,255,0.1) 0%, transparent 70%);
    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') center/cover no-repeat;
    opacity: 0.2;
    z-index: -1;
  }

  .hero-content {
    max-width: 800px;
    padding: 40px;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    box-shadow: 0 0 30px rgba(0, 198, 255, 0.3);
    transform: translateY(0);
    transition: transform 0.5s ease;
  }

  .hero-content:hover {
    transform: translateY(-10px);
  }

  h1, h2, h3, h4 {
    margin-bottom: 20px;
    font-weight: 300;
    line-height: 1.2;
  }

  h1 {
    font-size: 3rem;
    background: linear-gradient(90deg, var(--accent), var(--highlight));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 30px;
  }

  h2 {
    font-size: 2.2rem;
    color: var(--accent);
    position: relative;
    padding-bottom: 10px;
    margin-top: 60px;
  }

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

  h3 {
    font-size: 1.8rem;
    color: var(--highlight);
    margin-top: 40px;
  }

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

  .grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(500px, 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, 0.2);
    transition: all 0.3s ease;
    border: 1px solid rgba(0, 198, 255, 0.2);
    position: relative;
    overflow: hidden;
  }

  .card::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, var(--accent), var(--highlight));
    z-index: -1;
    border-radius: 16px;
    opacity: 0;
    transition: opacity 0.3s ease;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 198, 255, 0.3);
  }

  .card:hover::before {
    opacity: 0.3;
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
  }

  .card:hover .card-img {
    transform: scale(1.03);
  }

  code {
    background: rgba(0, 0, 0, 0.3);
    color: var(--highlight);
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
  }

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

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent);
    color: var(--primary);
    padding: 5px 10px;
    font-size: 0.8rem;
    border-bottom-left-radius: 5px;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    background: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
  }

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

  th {
    background: rgba(0, 198, 255, 0.2);
    color: var(--accent);
    font-weight: 300;
  }

  tr:hover {
    background: rgba(255, 255, 255, 0.05);
  }

  .btn {
    display: inline-block;
    padding: 12px 25px;
    background: linear-gradient(90deg, var(--accent), var(--highlight));
    color: var(--primary);
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    box-shadow: 0 5px 15px rgba(0, 198, 255, 0.3);
  }

  .btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 198, 255, 0.5);
  }

  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 198, 255, 0.2);
  }

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

  .nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 1rem;
    position: relative;
    transition: color 0.3s ease;
  }

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

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

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

  .reference {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(0, 0, 0, 0.7);
    padding: 10px 15px;
    border-radius: 50px;
    font-size: 0.8rem;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(0, 198, 255, 0.3);
  }

  @media (max-width: 768px) {
    .grid-container {
      grid-template-columns: 1fr;
    }

    .hero {
      height: auto;
      padding: 100px 20px;
    }

    h1 {
      font-size: 2rem;
    }

    h2 {
      font-size: 1.8rem;
    }

    h3 {
      font-size: 1.5rem;
    }

    .navbar {
      padding: 15px 20px;
    }

    .nav-links {
      display: none;
    }
  }

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

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

  .parallax-section {
    height: 400px;
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    position: relative;
    margin: 60px 0;
  }

  .parallax-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
  }

  .parallax-content {
    position: relative;
    z-index: 1;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0 20px;
  }