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

#gameArea {
    position: relative;
    width: 100%;
    height: 100%;
}

#background {
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: 1;
}

#spaceship {
    position: absolute;
    width: 50px;
    height: 50px;
    z-index: 3;
}

.planet {
    position: absolute;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    z-index: 2;
}