<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
div:first-child{
width: 200px;
height: 200px;
background-color: yellow;
}
div:last-child {
width: 200px;
height: 200px;
background-color: purple;
}
</style>
</head>
<body>
<div>1</div>
<div>2</div>
</body>
</html>
代码如上first-child就可以生效但是last-child就不行，这是为啥呢？
补充的截图
