:root {
    --primary: #0f2027;
    --secondary: #203a43;
    --accent: #2a5298;
    --highlight: #1e3c72;
    --text: #ffffff;
    --card-bg: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s ease;
  }

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.gstatic.com/s/roboto/v30/KFOmCnqEu92Fr1Mu4mxK.woff2') format('woff2');
  }

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

  body {
    background: linear-gradient(135deg, var(--primary), var(--secondary), var(--highlight));
    color: var(--text);
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  header {
    text-align: center;
    padding: 40px 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 {
    margin-bottom: 20px;
    font-weight: 700;
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(45deg, var(--accent), #6dd5ed);
    -webkit-background-clip: text;
    color: transparent;
    text-shadow: 0 0 10px rgba(0,0,0,0.3);
  }

  h2 {
    font-size: 1.8rem;
    color: #6dd5ed;
    position: relative;
    padding-bottom: 10px;
  }

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

  h3 {
    font-size: 1.5rem;
    color: #a8e6cf;
    margin-top: 30px;
  }

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

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

  .card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    transition: var(--transition);
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255,255,255,0.1);
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.4);
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    transition: var(--transition);
  }

  .card-img:hover {
    transform: scale(1.02);
  }

  pre {
    background: rgba(0,0,0,0.3);
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    overflow: auto;
    border-left: 4px solid var(--accent);
    font-family: monospace;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  code {
    color: #a8e6cf;
    background: transparent;
    padding: 2px 5px;
    border-radius: 3px;
  }

  .nav {
    position: sticky;
    top: 0;
    background: rgba(0,0,0,0.8);
    padding: 15px 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }

  .nav-list {
    display: flex;
    justify-content: center;
    list-style: none;
    flex-wrap: wrap;
  }

  .nav-item {
    margin: 0 15px;
  }

  .nav-link {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    padding: 5px 10px;
    border-radius: 5px;
    transition: var(--transition);
    position: relative;
  }

  .nav-link:hover {
    color: #6dd5ed;
  }

  .nav-link::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #6dd5ed;
    transition: var(--transition);
  }

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

  .notice {
    background: rgba(255,255,255,0.1);
    padding: 15px;
    border-radius: 10px;
    margin: 20px 0;
    text-align: center;
    border-left: 5px solid var(--accent);
  }

  .particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
  }

  .particle {
    position: absolute;
    width: 2px;
    height: 2px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 50%;
    animation: move 10s linear infinite;
  }

  @keyframes move {
    0% {
      transform: translate(0, 0);
      opacity: 0;
    }
    10% {
      opacity: 1;
    }
    90% {
      opacity: 1;
    }
    100% {
      transform: translate(1000px, 1000px);
      opacity: 0;
    }
  }

  .model-preview {
    width: 100%;
    height: 300px;
    background: url('https://images.gptkong.com/demo/sample3.png') center/cover no-repeat;
    border-radius: 10px;
    margin: 20px 0;
    position: relative;
    overflow: hidden;
  }

  .model-preview::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(30,60,114,0.7), rgba(42,82,152,0.7));
  }

  footer {
    text-align: center;
    padding: 30px;
    margin-top: 50px;
    background: rgba(0,0,0,0.3);
    border-top: 1px solid rgba(255,255,255,0.1);
  }

  @media (max-width: 768px) {
    .grid {
      grid-template-columns: 1fr;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.5rem;
    }
    
    .nav-list {
      flex-direction: column;
      align-items: center;
    }
    
    .nav-item {
      margin: 5px 0;
    }
  }