html, body {
    width:  100%;
    height: 100%;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

#game-canvas {
    position: absolute;
    top: 0;
    left: 0;
    z-index: -100;
}

#overlay-content {
    display: block;
    height: 100%;
    width: 100%;
}
#main-menu-wrapper {
    display: flex;
    height: 100%;
    width: 100%;
    justify-content: center;
}
#main-menu {
    display: flex;
    max-width: 50em;
    width: 100%;
    justify-self: center;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: gray;
    opacity: 50%;
}

#start-button {
    display: flex;
}
#exit-button {
    display: none;
}