/* 全局样式 */
  :root {
    --primary-color: #2D9CDB;
    --secondary-color: #27AE60;
    --accent-color: #333333;
    --background-color: #f5f5f5;
    --text-color: #333333;
    --font-heading: 'Roboto', Helvetica, sans-serif;
    --font-body: 'Open Sans', sans-serif;
  }

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

  body {
    font-family: var(--font-body);
    color: var(--text-color);
    background-color: var(--background-color);
    overflow-x: hidden;
  }

  a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
  }

  a:hover {
    color: var(--secondary-color);
  }

  header {
    background-color: var(--primary-color);
    padding: 20px;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  }

  .nav-tabs {
    display: flex;
    justify-content: center;
    list-style: none;
  }

  .nav-tabs li {
    margin: 0 15px;
  }

  .nav-tabs a {
    color: #fff;
    font-family: var(--font-heading);
    font-size: 18px;
    padding: 10px 15px;
    border-radius: 4px;
    transition: background-color 0.3s ease, transform 0.3s ease;
  }

  .nav-tabs a:hover, .nav-tabs a.active {
    background-color: var(--secondary-color);
    transform: scale(1.05);
  }

  main {
    padding: 100px 20px 20px 20px;
    max-width: 1200px;
    margin: 0 auto;
  }

  .section {
    margin-bottom: 50px;
  }

  .section h2 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 28px;
    border-bottom: 2px solid var(--secondary-color);
    display: inline-block;
  }

  .cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
  }

  .card {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
  }

  .card img {
    width: 100%;
    height: auto;
    border-radius: 4px;
    margin-bottom: 15px;
  }

  .card h3 {
    font-family: var(--font-heading);
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--secondary-color);
  }

  .card p {
    font-size: 16px;
    line-height: 1.6;
  }

  .prompt {
    text-align: center;
    padding: 20px;
    background-color: var(--accent-color);
    color: #fff;
    border-radius: 8px;
    margin-bottom: 50px;
    font-size: 18px;
  }

  .article {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  }

  .article h2 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 26px;
    border-bottom: 1px solid var(--secondary-color);
    padding-bottom: 10px;
  }

  .article h3 {
    font-family: var(--font-heading);
    color: var(--secondary-color);
    margin: 20px 0 10px 0;
    font-size: 20px;
  }

  .article p {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 15px;
  }

  .article pre {
    background-color: #f0f0f0;
    padding: 15px;
    border-radius: 4px;
    overflow-x: auto;
    margin-bottom: 15px;
  }

  .responsive-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 20px;
  }

  footer {
    text-align: center;
    padding: 20px;
    background-color: var(--primary-color);
    color: #fff;
    position: fixed;
    width: 100%;
    bottom: 0;
  }

  /* 微交互效果 */
  button, .button {
    background-color: var(--secondary-color);
    color: #fff;
    border: none;
    padding: 10px 20px;
    font-family: var(--font-heading);
    font-size: 16px;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.3s ease;
  }

  button:hover, .button:hover {
    background-color: var(--primary-color);
    transform: scale(1.05);
  }

  /* 响应式设计 */
  @media (max-width: 768px) {
    .nav-tabs {
      flex-direction: column;
      align-items: center;
    }

    .nav-tabs li {
      margin: 10px 0;
    }

    main {
      padding: 120px 10px 10px 10px;
    }

    .section h2 {
      font-size: 24px;
    }

    .article h2 {
      font-size: 22px;
    }
  }

  @media (max-width: 480px) {
    .nav-tabs a {
      font-size: 16px;
      padding: 8px 12px;
    }

    .section h2 {
      font-size: 20px;
    }

    .card h3 {
      font-size: 18px;
    }

    .card p {
      font-size: 14px;
    }

    .prompt {
      font-size: 16px;
    }

    .article {
      padding: 20px;
    }
  }