在每个<p>之前插入的内容和样式 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    p:before {
      content: "Read this -";
      background-color: yellow;
      color: red;
      font-weight: bold;
    }
  </style>
</head>

<body>
  <p>My name is Donald</p>
  <p>I live in Ducksburg</p>

  <p><b>注意:</b> :before 作用于 IE8, DOCTYPE 必须已经声明.</p>

</body>
</html>
        