.loginbody {
    /*background: url(imgs/login_bg.jpg);*/
    background: #0075b8;
    background-size: cover;
}
.loginwin{
    position:fixed;
    top:50%;
    left:50%;
    background:#EEE;
    border:1px solid #CCC;
    width:400px;
    height:300px;
}