:root {
    --primary: linear-gradient(135deg, #0D47A1, #4527A0);
    --secondary: #2E3A59;
    --accent: #FFA000;
    --text: #FFFFFF;
    --card-bg: rgba(255,255,255,0.1);
    --font-main: 'Roboto', sans-serif;
  }

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

  body {
    background: var(--primary);
    color: var(--text);
    font-family: var(--font-main);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  .header {
    padding: 30px 0;
    text-align: center;
    position: relative;
  }

  .header::after {
    content: "";
    display: block;
    width: 80%;
    height: 2px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.5), transparent);
    margin: 20px auto;
  }

  h1, h2, h3, h4 {
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  }

  h1 { font-size: 2.5rem; }
  h2 { font-size: 2rem; }
  h3 { font-size: 1.5rem; }
  h4 { font-size: 1.2rem; }

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

  .hero {
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    margin-bottom: 50px;
  }

  .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 {
    text-align: center;
    max-width: 800px;
    padding: 40px;
    background: rgba(0,0,0,0.5);
    border-radius: 15px;
    backdrop-filter: blur(10px);
    animation: fadeIn 1.5s ease;
  }

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

  .notice {
    background: rgba(255,255,255,0.1);
    padding: 15px;
    border-left: 3px solid var(--accent);
    margin: 30px 0;
    font-size: 0.9rem;
  }

  .content-section {
    margin: 50px 0;
    padding: 30px;
    background: var(--card-bg);
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transition: transform 0.3s ease;
  }

  .content-section:hover {
    transform: translateY(-5px);
  }

  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
  }

  .card {
    background: rgba(255,255,255,0.1);
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
    background: rgba(255,255,255,0.15);
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
  }

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

  pre {
    background: rgba(0,0,0,0.3);
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    border-left: 3px solid var(--accent);
  }

  code {
    font-family: 'Courier New', monospace;
    background: rgba(0,0,0,0.2);
    padding: 2px 5px;
    border-radius: 3px;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    background: rgba(255,255,255,0.1);
  }

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

  th {
    background: rgba(0,0,0,0.2);
    font-weight: 700;
  }

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

  .nav-links {
    display: flex;
    justify-content: center;
    margin: 40px 0;
    flex-wrap: wrap;
  }

  .nav-link {
    margin: 0 15px;
    padding: 10px 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 30px;
    text-decoration: none;
    color: var(--text);
    transition: all 0.3s ease;
    font-weight: 500;
  }

  .nav-link:hover {
    background: var(--accent);
    transform: translateY(-3px);
  }

  .footer {
    text-align: center;
    padding: 40px 0;
    margin-top: 50px;
    border-top: 1px solid rgba(255,255,255,0.1);
  }

  @media (max-width: 768px) {
    .hero {
      height: 300px;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.7rem; }
    h3 { font-size: 1.3rem; }
    
    .content-section {
      padding: 20px;
    }
    
    .grid {
      grid-template-columns: 1fr;
    }
  }

  /* Aurora animation */
  .aurora-effect {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.3;
    background: linear-gradient(135deg, #0D47A1, #4527A0);
    animation: auroraMove 15s infinite alternate;
  }

  @keyframes auroraMove {
    0% {
      background-position: 0% 50%;
    }
    50% {
      background-position: 100% 50%;
    }
    100% {
      background-position: 0% 50%;
    }
  }

  /* Floating elements */
  .float-element {
    position: absolute;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: rgba(255,255,255,0.05);
    filter: blur(20px);
    animation: float 15s infinite ease-in-out;
  }

  @keyframes float {
    0%, 100% {
      transform: translate(0, 0);
    }
    25% {
      transform: translate(50px, 50px);
    }
    50% {
      transform: translate(0, 100px);
    }
    75% {
      transform: translate(-50px, 50px);
    }
  }