<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
<title>boardTest</title>
<style>
p{
margin: 50px auto;
padding: 5px 10px 5px 10px;
color: red;
text-align: center;
width: 60px;
}
p:first-child{
border-bottom: 1px solid red;
}
p:last-child{
position: relative;
}
p:last-child:after {
position: absolute;
content: '';
width: 100%;
left: 0;
bottom: 0;
height: 1px;
background-color: red;
-webkit-transform: scale(1,0.5);
transform: scale(1,0.5);
-webkit-transform-origin: center bottom;
transform-origin: center bottom
}

</style>
</head>
<body>
<div>
<p>点击1</p>
<p>点击2</p>
</div>
</body>
</html>