:root {
    --primary: #2C3E50;
    --secondary: #3498DB;
    --accent: #E67E22;
    --light: #ECF0F1;
    --dark: #1A252F;
    --text: #34495E;
    --white: #FFFFFF;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;700&display=swap');
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    overflow-x: hidden;
  }

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

  .hero {
    height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.8)), 
                url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    color: var(--white);
    position: relative;
    overflow: hidden;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 50%, rgba(52, 152, 219, 0.3) 0%, transparent 50%);
  }

  .hero-content {
    max-width: 800px;
    z-index: 1;
    animation: fadeIn 1s ease-out;
  }

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

  .hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    background: linear-gradient(90deg, var(--white), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
  }

  .notice {
    background: var(--accent);
    color: var(--white);
    padding: 15px;
    text-align: center;
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  }

  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(44, 62, 80, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .navbar-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .nav-links {
    display: flex;
    list-style: none;
  }

  .nav-links li {
    margin-left: 30px;
  }

  .nav-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
  }

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

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

  article {
    padding: 100px 0;
    background: var(--white);
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.05);
  }

  .article-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
  }

  article h2 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    color: var(--primary);
    position: relative;
    padding-bottom: 15px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 2px;
  }

  article h3 {
    font-size: 1.8rem;
    margin: 40px 0 20px;
    color: var(--primary);
  }

  article p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    line-height: 1.8;
  }

  .code-container {
    position: relative;
    margin: 30px 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  }

  pre {
    margin: 0;
    padding: 20px;
    background: #282C34;
    color: #ABB2BF;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.5;
    overflow-x: auto;
  }

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

  .language-css {
    color: #56B6C2;
  }

  .property {
    color: #E06C75;
  }

  .value {
    color: #98C379;
  }

  .selector {
    color: #E5C07B;
  }

  .image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .image-card {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

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

  .image-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
  }

  .image-card:hover img {
    transform: scale(1.05);
  }

  .image-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 15px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
    color: var(--white);
    opacity: 0;
    transition: var(--transition);
  }

  .image-card:hover .image-caption {
    opacity: 1;
  }

  .callout {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1) 0%, rgba(230, 126, 34, 0.1) 100%);
    border-left: 4px solid var(--accent);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
  }

  .footer {
    background: var(--primary);
    color: var(--white);
    padding: 50px 0;
    text-align: center;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    list-style: none;
    margin: 20px 0;
  }

  .footer-links li {
    margin: 0 15px;
  }

  .footer-links a {
    color: var(--white);
    text-decoration: none;
    transition: var(--transition);
  }

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

  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.5rem;
    }
    
    .nav-links {
      display: none;
    }
    
    article h2 {
      font-size: 2rem;
    }
    
    article h3 {
      font-size: 1.5rem;
    }
  }