:root {
    --primary-color: #0d1b2a;
    --secondary-color: #1b263b;
    --accent-color: #ff6b35;
    --highlight-color: #4cc9f0;
    --text-color: #ffffff;
    --text-secondary: #dddddd;
    --card-bg: rgba(27, 38, 59, 0.8);
    --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;500;700&display=swap');
  }

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

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

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

  .header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(13, 27, 42, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    padding: 15px 0;
  }

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

  .logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--highlight-color);
    text-decoration: none;
    display: flex;
    align-items: center;
  }

  .logo-icon {
    margin-right: 10px;
    width: 30px;
    height: 30px;
    background: linear-gradient(45deg, var(--accent-color), var(--highlight-color));
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
  }

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

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

  .nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    transition: var(--transition);
    padding: 8px 12px;
    border-radius: 4px;
  }

  .nav-links a:hover {
    background: rgba(255, 107, 53, 0.2);
    color: var(--accent-color);
  }

  .dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--secondary-color);
    border-radius: 4px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    min-width: 200px;
    padding: 10px 0;
    transform: translateY(10px);
  }

  .nav-links li:hover .dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .dropdown li {
    margin: 0;
    padding: 0;
  }

  .dropdown a {
    display: block;
    padding: 10px 20px;
  }

  .dropdown a:hover {
    background: rgba(255, 107, 53, 0.3);
  }

  .hero {
    padding: 180px 0 100px;
    position: relative;
    overflow: hidden;
  }

  .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: 0.1;
    z-index: -1;
  }

  .hero-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    position: relative;
  }

  .hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    background: linear-gradient(90deg, var(--highlight-color), var(--accent-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    line-height: 1.2;
  }

  .hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
  }

  .hero-decoration {
    position: absolute;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(76, 201, 240, 0.2) 0%, rgba(76, 201, 240, 0) 70%);
    z-index: -1;
  }

  .decoration-1 {
    top: -50px;
    left: -50px;
  }

  .decoration-2 {
    bottom: -50px;
    right: -50px;
  }

  .notice {
    background: rgba(255, 107, 53, 0.1);
    border-left: 4px solid var(--accent-color);
    padding: 15px;
    margin: 30px 0;
    border-radius: 0 4px 4px 0;
    font-size: 0.9rem;
  }

  .content-section {
    padding: 80px 0;
    position: relative;
  }

  .content-section:nth-child(even) {
    background: rgba(13, 27, 42, 0.5);
  }

  .section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 40px;
    position: relative;
    display: inline-block;
  }

  .section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), var(--highlight-color));
    border-radius: 2px;
  }

  .article-container {
    max-width: 900px;
    margin: 0 auto;
  }

  article {
    padding: 40px 0;
  }

  article h2 {
    font-size: 2rem;
    font-weight: 700;
    margin: 40px 0 20px;
    color: var(--highlight-color);
  }

  article h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 30px 0 15px;
    color: var(--accent-color);
  }

  article p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 20px;
  }

  article strong {
    color: var(--highlight-color);
    font-weight: 500;
  }

  .card {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 30px;
    margin: 30px 0;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 107, 53, 0.3);
  }

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

  .image-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    height: 300px;
    transition: var(--transition);
  }

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

  .image-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
  }

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

  .image-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(13, 27, 42, 0.7), transparent);
  }

  pre {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    border-left: 4px solid var(--accent-color);
    position: relative;
  }

  pre code {
    display: block;
    color: var(--highlight-color);
  }

  .copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: var(--transition);
  }

  .copy-btn:hover {
    background: rgba(255, 107, 53, 0.3);
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    background: var(--card-bg);
    border-radius: 8px;
    overflow: hidden;
  }

  thead {
    background: linear-gradient(90deg, var(--accent-color), var(--highlight-color));
  }

  th {
    padding: 15px;
    text-align: left;
    color: var(--primary-color);
    font-weight: 600;
  }

  tbody tr:nth-child(even) {
    background: rgba(27, 38, 59, 0.6);
  }

  tbody tr:nth-child(odd) {
    background: rgba(13, 27, 42, 0.6);
  }

  td {
    padding: 12px 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  }

  .footer {
    background: var(--primary-color);
    padding: 60px 0 30px;
    text-align: center;
    position: relative;
  }

  .footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
  }

  .footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--highlight-color);
    margin-bottom: 20px;
    display: inline-block;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    list-style: none;
    margin-bottom: 30px;
  }

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

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

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

  .copyright {
    color: var(--text-secondary);
    font-size: 0.9rem;
    opacity: 0.7;
  }

  .reference {
    background: rgba(76, 201, 240, 0.1);
    padding: 15px;
    border-radius: 8px;
    margin: 40px 0;
    text-align: center;
    font-size: 0.9rem;
    color: var(--highlight-color);
  }

  @media (max-width: 992px) {
    .hero-title {
      font-size: 2.8rem;
    }
    
    .section-title {
      font-size: 2rem;
    }
    
    article h2 {
      font-size: 1.8rem;
    }
    
    article h3 {
      font-size: 1.3rem;
    }
  }

  @media (max-width: 768px) {
    .nav-container {
      flex-direction: column;
    }
    
    .logo {
      margin-bottom: 15px;
    }
    
    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }
    
    .nav-links li {
      margin: 5px 10px;
    }
    
    .hero {
      padding: 150px 0 80px;
    }
    
    .hero-title {
      font-size: 2.2rem;
    }
    
    .hero-subtitle {
      font-size: 1rem;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
  }

  @media (max-width: 576px) {
    .hero-title {
      font-size: 1.8rem;
    }
    
    .section-title {
      font-size: 1.6rem;
    }
    
    article h2 {
      font-size: 1.5rem;
    }
    
    article p {
      font-size: 1rem;
    }
    
    .card {
      padding: 20px;
    }
  }

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

  @keyframes pulse {
    0%, 100% {
      opacity: 1;
    }
    50% {
      opacity: 0.5;
    }
  }

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

  .pulse {
    animation: pulse 2s ease-in-out infinite;
  }