<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>css</title>
<style type="text/css">
div{
width:300px;height:100px;line-height:100px;background:#E1EFFF;text-align:center;
border:2px red solid; border-radius:10px;
box-shadow:20px 20px gray;
outline:10px solid green;
}
input,textarea{outline:none}
</style>
</head>
<body>
<div>我要好好学习</div>
<br>
<input type="text">
<br>
<br>
<textarea name="" id="" cols="30" rows="10"></textarea>
</body>
</html>
如果不加outline:none则在网页面上点选时,会有一个粗蓝的方框,
返回值: