I would like to apply the next code only when using X11:

/* Remove unwanted margin of menupopup just in linux */
    
    @media (-moz-platform: linux) {
        #appMenu-popup {
            --panel-shadow-margin: 0px !important;
            --panel-padding-block: 0px !important;
        }
    }

this code when using Wayland makes the popup unaligned.