.centered {
    display: block;
    width: 400px;
    height: 200px;
     position: fixed;
    top: 50%;
    left: 50%;
    margin-top: -100px;
    margin-left: -200px;
}
#container{
    width: 100%;
    height: 100%;
    background: #EAF4FD;
}