Overlay button close lightbox and menu in mobile mode

Site URL: https://www.fernezchambon-architectes.com/

The password is : okokokok
Hello ,
I encounter a big problem on pages, in mobile mode the button close the lightbox and the menu is superimposed.
I would like to find a solution to fix this problem please.
The close lightbox button also doesn't work

Hi. It looks like you solved with this CSS?

@media (max-width: 768px) {
    #lightbox_background {
        height:100% !important;
        width: 100% !important;
        background-color: #fff !important;
        opacity: 1 !important
    }

    #lightbox_overlay {
        position: fixed;
        height: 101%;
        width: 101%;
        left: 0;
        top: 70px !important;
        z-index: 1000
    }
}