* {
    padding: 0;
    margin: 0;
}

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

#game-launch {
    display: block;
}

#content {
    padding: 20px;
    display: none;
    align-items: center;
    justify-content: center;
    position: fixed;
    left: 0;
    top: 0;
    width: calc(100% - 40px);
    height: calc(100% - 40px);
    z-index: 1000;
    overflow: hidden;
    background-color: black;
    color: whitesmoke;
    font-size: 18px;
}

#content.show {
    display: flex;
}