<!DOCTYPE html>
<html lang="en" ng-app="test">
<head>
<meta charset="UTF-8">
<title></title>
<style>
body{
text-align: center;
font-family: "微软雅黑"
}
.border-label{
position: relative;
width: 150px;
height:150px;
margin: auto;
margin-top:150px;
}
.border-label:hover .border-change{
transform: rotate(180deg);
}
.border-label:hover .border-change-start{
display: none;
}
.border-label:hover .border-change-go{
display: block;
}
.border-change{
position: relative;
width: 150px;
height:150px;
border-radius: 50%;
border-width: 5px;
border-style: solid;
border-bottom-color: #ADFF2F;
border-top-color: #9BCD9B;
border-left-color: #9BCD9B;
border-right-color: #ADFF2F;
transition: all 0.8s ease-in-out;
z-index: 2;
cursor: pointer;
}
.border-change-context{
position: absolute;
width: 150px;
height: 150px;
line-height:150px;
text-align: center;
left: 5px;
top:5px;
font-size: 50px;
}
.border-change-start{
color:#9BCD9B;
}
.border-change-go{
color:#ADFF2F;
display: none;
}
.blog-head{
color:#ADFF2F;
padding-top: 10px;
padding-bottom: 10px;
font-size: 20px;
}
</style>
</head>
<body>
<div class="border-label">
<div class="border-change"></div>
<div class="border-change-context border-change-start">
Start
</div>
<div class="border-change-context border-change-go">
Go!
</div>
</div>
<p class="blog-head">开始</p>
</body>
</html>
原文：http://www.cnblogs.com/lily2015/p/4661937.html