body, html {
    height: 100%;
    background-color: black;
    color: white;
}

body {
    margin: 0;
    overflow: hidden;
}

body, #box, #top {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
}
#display {
    width: 100%;
    height: 100%
}