/* 全局重置 */
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }

  /* 基本字体与背景 */
  body {
    font-family: 'Roboto', sans-serif;
    background: radial-gradient(circle, rgba(255, 87, 34, 0.8), transparent);
    color: #333;
    line-height: 1.6;
    padding: 20px;
    animation: aurora-move 15s linear infinite;
  }

  /* 头部样式 */
  header {
    position: fixed;
    top: 0;
    width: 100%;
    background: linear-gradient(90deg, #0074D9, #FFA500);
    padding: 15px 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 1000;
  }

  /* 导航栏样式 */
  nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
  }

  nav ul li {
    margin: 0 20px;
  }

  nav ul li a {
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    transition: color 0.3s;
  }

  nav ul li a:hover {
    color: #FFD700;
  }

  /* 主内容区域 */
  main {
    margin-top: 80px;
    padding: 20px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
  }

  /* 章节标题 */
  h1, h2, h3, h4 {
    color: #0074D9;
    margin-bottom: 15px;
  }

  /* 段落样式 */
  p {
    margin-bottom: 15px;
    font-size: 16px;
  }

  /* 代码块样式 */
  pre {
    background: #f5f5f5;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin-bottom: 15px;
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    background: #eaeaea;
    padding: 2px 4px;
    border-radius: 3px;
  }

  /* 表格样式 */
  table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 15px;
  }

  table, th, td {
    border: 1px solid #ddd;
  }

  th, td {
    padding: 10px;
    text-align: left;
  }

  th {
    background-color: #0074D9;
    color: #fff;
  }

  /* 卡片样式 */
  .card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    padding: 20px;
    margin-bottom: 20px;
    transition: transform 0.3s;
  }

  .card:hover {
    transform: translateY(-5px);
  }

  /* 按钮样式 */
  .button {
    background-color: #FFA500;
    color: #fff;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: transform 0.3s ease, background-color 0.3s ease;
  }

  .button:hover {
    transform: scale(1.05);
    background-color: #FFB74D;
  }

  /* 图片样式 */
  img {
    max-width: 100%;
    height: auto;
    border-radius: 5px;
    margin-bottom: 15px;
  }

  /* 页脚样式 */
  footer {
    text-align: center;
    padding: 20px;
    background: #0074D9;
    color: #fff;
    position: fixed;
    width: 100%;
    bottom: 0;
  }

  /* 响应式设计 */
  @media (max-width: 1440px) {
    body {
      padding: 15px;
    }
    nav ul li a {
      font-size: 16px;
    }
  }

  @media (max-width: 1200px) {
    main {
      padding: 15px;
    }
    nav ul li {
      margin: 0 15px;
    }
  }

  @media (max-width: 1024px) {
    nav ul {
      flex-direction: column;
    }
    nav ul li {
      margin: 10px 0;
    }
    h1 {
      font-size: 26px;
    }
    h2 {
      font-size: 22px;
    }
  }

  @media (max-width: 768px) {
    h1 {
      font-size: 24px;
    }
    h2 {
      font-size: 20px;
    }
    p {
      font-size: 14px;
    }
    .button {
      padding: 8px 16px;
      font-size: 14px;
    }
  }

  @media (max-width: 480px) {
    nav ul li a {
      font-size: 14px;
    }
    h1 {
      font-size: 20px;
    }
    h2 {
      font-size: 18px;
    }
    p {
      font-size: 12px;
    }
    .button {
      padding: 6px 12px;
      font-size: 12px;
    }
  }

  @media (max-width: 320px) {
    body {
      padding: 10px;
    }
    nav ul {
      flex-direction: column;
    }
    nav ul li {
      margin: 8px 0;
    }
    h1 {
      font-size: 18px;
    }
    h2 {
      font-size: 16px;
    }
    p {
      font-size: 12px;
    }
  }

  /* 动画定义 */
  @keyframes aurora-move {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }

  .animated-background {
    background: radial-gradient(circle, rgba(255, 87, 34, 0.8), transparent);
    animation: aurora-move 15s linear infinite;
  }