设置元素的左，右，顶部和底部填充
的 填充属性集左，右，顶和元件的底部填充。您可以尝试运行以下代码来实现padding属性。
示例
<html>
<head>
</head>
<body>
<p style = "padding: 25px; border:2px solid orange;">
This is a paragraph.
</p>
<p style = "padding:20px 4%; border:2px solid red;">
This is another paragraph.
</p>
<p style = "padding: 15px 3% 10px; border:1px solid maroon;">
Top padding will be 15px, left and right padding will be 3% of the total width of the document, bottom padding will be 10px
</p>
</body>
</html>