css3+伪元素如何实现鼠标移入时下划线展开特效？
网友解答: 完整代码<!DOCTYPE html<html<head<meta charset="UTF-8"<title鼠标移入下划线展开</tit
完整代码
<!DOCTYPE html
<html
<head
<meta charset="UTF-8"
<title鼠标移入下划线展开</title
<style type="text/css"
#underline{
width: 200px;
height: 50px;
background: #ddd;
margin: 20px;
position: relative;
}
#underline:after{
content: "";
width: 0;
height: 5px;
background: blue;
position: absolute;
top: 100%;
left: 50%;
transition: all .8s;
}
#underline:hover:after{
left: 0%;
width: 100%;
}
</style
</head
<body
<div id="underline"</div
</body
</html