#login {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    -webkit-transform: translate(-50%, -50%);
    -o-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
}

.red_background {
    background-color: red;
}

.green_background {
    background-color: green;
}

.yellow_background {
    background-color: yellow;
}

.orange_background {
    background-color: orange;
}

.white_background {
    background-color: white;
}