<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<style>
*{
margin: 0;
padding: 0;
}
body{
background: #333;
}
.btn{
display: block;
width: 100px;
height: 40px;
border: 2px solid white;
position: absolute;
margin: auto;
top: 0;
left: 0;
right: 0;
bottom: 0;
color: white;
line-height: 40px;
text-align: center;
}
.line{
display: block;
position: absolute;
/*平滑过渡效果 css3属性*/
transition: all 5s;
-webkit-transition: all 0.3s;
-ms-transition: all 0.5s;
-moz-transition: all 0.5s;
background: white;
}
.lineTop{
width: 0;
height: 2px;
top: -2px;
right: -100%;
}
.btn:hover .lineTop{
width: 100%;
right: 0;
}
.lineBottom{
width: 0;
height: 2px;
bottom: -2px;
left: -100%;
}
.btn:hover .lineBottom{
width: 100%;
left: 0;
}
.lineLeft{
width: 2px;
height: 0;
left: -2px;
top: -100%;
}
.btn:hover .lineLeft{
height: 100%;
top: 0;
}
.lineRight{
width: 2px;
height: 0;
right: -2px;
bottom: -100%;
}
.btn:hover .lineRight{
height: 100%;
bottom: 0;
}
</style>
<body>
<a class="btn">
<span class="line lineTop"></span>
<span class="line lineLeft"></span>
<span class="line lineRight"></span>
<span class="line lineBottom"></span>
退货
</a>
</body>
</html>