style.css

.style-mainScreen {
    float: left;
    width: 90px;
    height: 75px;
    border: solid 1px black;
}

.style-nextScreen {
    float: left;
    width: 200px;
    margin: 0 10px 0 10px;
    min-height: 400px;
    border: solid 1px black;
}

.style-controller {
    float: left;
    width: 120px;
    min-height: 400px;
    border: solid 1px black;
}

.center-endgame {
    display: flex;
    justify-content: center;
    align-items: center;
}

.center-endgame span {
    font-size: 20px;
    font-weight: 700;
    text-transform: capitalize;
}

.hide-endgame {
    display: none;
}

.show-endgame {
    display: flex;
}

a.button {
    -webkit-appearance: button;
    -moz-appearance: button;
    appearance: button;
    text-decoration: none;
    color: initial;
    display: flex;
    justify-content: center;
}