/* 重置样式 */
   * {
    box-sizing: border-box;
  }
  
  html, body, div, span, h1, h2, h3, h4, h5, h6, p, a, img, ul, li {
    margin: 0;
    padding: 0;
    border: 0;
  }
  
  a {
    text-decoration: none;
    color: inherit;
  }
  
  ul, li {
    list-style: none;
  }