:root {
    --primary: #1E90FF;
    --secondary: #FFA500;
    --accent: #FF8C00;
    --light: #F9F9F9;
    --dark: #333333;
    --gray: #E0E0E0;
    --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', 'Open Sans', sans-serif;
    color: var(--dark);
    background: var(--light);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  .hero {
    background: linear-gradient(135deg, var(--primary) 30%, var(--secondary) 70%);
    color: white;
    padding: 100px 0;
    text-align: center;
    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: 0;
  }

  .hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
  }

  .hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  }

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

  .notice {
    background: rgba(255, 255, 255, 0.2);
    padding: 15px;
    border-radius: 8px;
    margin-top: 30px;
    display: inline-block;
    backdrop-filter: blur(5px);
  }

  .content-section {
    padding: 80px 0;
    background: white;
  }

  .content-section:nth-child(even) {
    background: var(--light);
  }

  .section-title {
    text-align: center;
    margin-bottom: 50px;
    position: relative;
  }

  .section-title h2 {
    font-size: 2.2rem;
    color: var(--primary);
    display: inline-block;
    padding-bottom: 10px;
  }

  .section-title h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--secondary);
  }

  article {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  }

  article h2 {
    color: var(--primary);
    font-size: 1.8rem;
    margin-bottom: 30px;
    text-align: center;
  }

  article h3 {
    color: var(--secondary);
    font-size: 1.4rem;
    margin: 30px 0 15px;
    position: relative;
    padding-left: 15px;
  }

  article h3::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 5px;
    height: 20px;
    background: var(--primary);
    border-radius: 3px;
  }

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

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

  pre {
    background: #282c34;
    color: #abb2bf;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 30px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
  }

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

  .image-card {
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
  }

  .image-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
  }

  .image-card img {
    width: 100%;
    height: auto;
    display: block;
  }

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

  .nav-tab {
    padding: 10px 20px;
    margin: 0 10px;
    background: transparent;
    border: none;
    color: var(--dark);
    font-weight: bold;
    cursor: pointer;
    position: relative;
    transition: var(--transition);
  }

  .nav-tab::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
  }

  .nav-tab:hover::after,
  .nav-tab.active::after {
    width: 100%;
  }

  .nav-tab:hover,
  .nav-tab.active {
    color: var(--primary);
  }

  .tab-content {
    display: none;
  }

  .tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
  }

  @keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
  }

  .button {
    display: inline-block;
    padding: 12px 24px;
    background: var(--secondary);
    color: white;
    border: none;
    border-radius: 30px;
    font-weight: bold;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  }

  .button:hover {
    background: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
  }

  .progress-bar {
    height: 5px;
    width: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    animation: loading 2s ease infinite;
  }

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

  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.2rem;
    }
    
    .hero p {
      font-size: 1rem;
    }
    
    article {
      padding: 20px;
    }
    
    .image-grid {
      grid-template-columns: 1fr;
    }
  }