<html>
<head>
<style type="text/css">
#login{
300px;
height: 200px;
position: absolute;
left: 50%;
top: 50%;
margin-left: -150px;
margin-top: -100px;
background: #BABABA;
}
a{
text-decoration:none;
color:#f0000f;
}
a:hover{
position: relative;
left: 1px;
top: 1px;
cursor:pointer;
}
</style>
</head>
<body>
<div id="login"><a href="#">登陆123</a></div>
</body>
</html>