:root {
    --primary: #2c3e50;
    --secondary: #8e44ad;
    --accent: #f39c12;
    --text: #2c3e50;
    --light: #ecf0f1;
    --dark: #1a1a1a;
    --gradient: linear-gradient(135deg, var(--primary), var(--secondary));
    --card-shadow: 0 10px 30px 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: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background-color: #f9f9f9;
    overflow-x: hidden;
  }

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

  header {
    background: var(--gradient);
    color: white;
    padding: 2rem 0;
    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;
    background-size: cover;
    opacity: 0.1;
    z-index: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
  }

  .header-content h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  }

  .header-content p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
  }

  .notice {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 1rem;
    border-radius: 8px;
    margin-top: 2rem;
    display: inline-block;
    border: 1px solid rgba(255, 255, 255, 0.3);
  }

  .nav-container {
    background: rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
  }

  nav {
    display: flex;
    justify-content: center;
    gap: 2rem;
  }

  nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    position: relative;
    transition: var(--transition);
  }

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

  nav a:hover::after {
    width: 100%;
  }

  main {
    padding: 3rem 0;
  }

  article {
    background: white;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    padding: 2rem;
    margin-bottom: 3rem;
  }

  article h2 {
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.5rem;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100px;
    height: 4px;
    background: var(--gradient);
    border-radius: 2px;
  }

  article h3 {
    color: var(--secondary);
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
  }

  article p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
  }

  article span {
    font-weight: bold;
    color: var(--secondary);
  }

  pre {
    background: #f5f5f5;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow-x: auto;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--primary);
    color: white;
    padding: 0.2rem 0.8rem;
    border-radius: 0 0 0 8px;
    font-size: 0.8rem;
  }

  code {
    font-family: 'Courier New', monospace;
    color: #e74c3c;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  }

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

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

  tr:nth-child(even) {
    background: #f9f9f9;
  }

  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
  }

  .card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
  }

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

  .card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-bottom: 1px solid #eee;
  }

  .card-content {
    padding: 1.5rem;
  }

  .card h4 {
    color: var(--primary);
    margin-bottom: 0.5rem;
  }

  .card p {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 1rem;
  }

  .features {
    list-style: none;
  }

  .features li {
    padding: 0.5rem 0;
    position: relative;
    padding-left: 1.5rem;
  }

  .features li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent);
  }

  footer {
    background: var(--dark);
    color: white;
    padding: 3rem 0;
    text-align: center;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
  }

  .footer-content p {
    margin-bottom: 1rem;
  }

  .social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
  }

  .social-links a {
    color: white;
    text-decoration: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
  }

  .social-links a:hover {
    background: var(--accent);
    transform: translateY(-3px);
  }

  @media (max-width: 768px) {
    .header-content h1 {
      font-size: 2rem;
    }

    nav {
      flex-direction: column;
      gap: 0.5rem;
      align-items: center;
    }

    .gallery {
      grid-template-columns: 1fr;
    }
  }

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

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