.menu-background {
    display: block;
    position: absolute;
    top:0;
    left:0;
    right:0;
    bottom:0;
    opacity: 0;
    background-color: #000000;
    transition: opacity 0.3s ease-out;
    pointer-events: none;
    z-index:99;
}

.menu-background.show {
    pointer-events: all;
    opacity: 0.3;
}