:root {
    --primary: #1e3c72;
    --secondary: #2a5298;
    --accent: #FFA500;
    --text: #333333;
    --light: #ffffff;
    --dark: #1a1a1a;
    --gray: #f5f5f5;
    --radius: 12px;
    --shadow: 0 8px 24px rgba(0,0,0,0.1);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

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

  body {
    font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
    padding-bottom: 60px;
  }

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

  header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--light);
    padding: 60px 0 80px;
    text-align: center;
    clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
    margin-bottom: 60px;
    position: relative;
    overflow: hidden;
  }

  header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
    background-size: contain;
    opacity: 0.1;
  }

  h1 {
    font-size: 2.8rem;
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
  }

  h1::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
  }

  .tagline {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 30px;
    opacity: 0.9;
  }

  .notice {
    background: rgba(255,255,255,0.2);
    padding: 12px 20px;
    border-radius: var(--radius);
    display: inline-block;
    font-size: 0.9rem;
    backdrop-filter: blur(5px);
    margin-top: 30px;
  }

  article {
    background: var(--light);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 40px;
    margin-bottom: 40px;
  }

  h2 {
    color: var(--primary);
    font-size: 1.8rem;
    margin: 30px 0 20px;
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), transparent);
  }

  h3 {
    color: var(--secondary);
    font-size: 1.4rem;
    margin: 25px 0 15px;
  }

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

  pre {
    background: var(--dark);
    color: #f8f8f2;
    padding: 20px;
    border-radius: var(--radius);
    margin: 20px 0;
    overflow-x: auto;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
    position: relative;
  }

  pre::before {
    content: "CSS";
    position: absolute;
    top: 0;
    left: 0;
    background: var(--accent);
    color: var(--light);
    padding: 2px 10px;
    border-radius: var(--radius) 0 var(--radius) 0;
    font-size: 0.8rem;
    font-weight: bold;
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.95rem;
  }

  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }

  .gallery img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--radius);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: var(--transition);
  }

  .gallery img:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.15);
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border-radius: var(--radius);
    overflow: hidden;
  }

  th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid rgba(0,0,0,0.05);
  }

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

  tr:nth-child(even) {
    background: var(--gray);
  }

  tr:hover {
    background: rgba(255,165,0,0.05);
  }

  .card-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px 0;
  }

  .card {
    background: var(--light);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 25px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
  }

  .card::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent);
  }

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

  .card h4 {
    color: var(--primary);
    margin-bottom: 15px;
  }

  @media (max-width: 768px) {
    h1 {
      font-size: 2.2rem;
    }
    
    article {
      padding: 30px 20px;
    }
    
    .gallery {
      grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
  }

  @media (max-width: 480px) {
    header {
      padding: 40px 0 60px;
    }
    
    h1 {
      font-size: 1.8rem;
    }
    
    .tagline {
      font-size: 1rem;
    }
    
    pre {
      padding: 15px;
      font-size: 0.85rem;
    }
  }

  /* Animations */
  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
  }

  .floating {
    animation: float 3s ease-in-out infinite;
  }