html, body, div {
    padding: 0;
    margin: 0;
}
.center {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}
.universe {
    background-color: black;
}
.star {
    border-radius: 50%;
    background-color: orange;
}
.ship {
    background-color: lightblue;
}