Module:Random slideshow/styles.css

/* Hide the toggle gallery button */
div.randomSlideshow-container > ul.gallery.mw-gallery-slideshow > li.gallerycarousel > div > div > div > span:nth-child(2)  {
	display: none;
}

/* On mobile devices, only show the first four images */
@media screen and ( max-width: 720px ) {
	div.randomSlideshow-container > ul.gallery.mw-gallery-slideshow > li:nth-child(n+5)  {
		display: none;
	}
	div.randomSlideshow-container > ul.gallery.mw-gallery-slideshow {
	    padding-left:0;
	    padding-right:0;
	    display:flex;
	    flex-wrap:wrap;
	    justify-content: space-around;
	    align-items: flex-start;
	}
	div.randomSlideshow-container > ul.gallery.mw-gallery-slideshow > li {
	    width:initial !important; /* overrides inline style */
	    margin:0 0.5em;
	}
	div.randomSlideshow-container > ul.gallery.mw-gallery-slideshow > li > div > div > div {
	    margin:0.5em 0 !important; /* overrides inline style */
	}
}