body, html {
    height: 100%;
    margin: 0;
}

a {
    opacity: 0;
    color: gray;
}

a:hover {
    opacity: 0.1;
}

#bg {
    height: 100%;
    background: no-repeat center;
    background-size: contain;
}

#configure {
    float: left;
    margin: 5px;
}