roomy like

/* Recreates the basic functionality of the popular Roomy Bookmarks Toolbar add-on:
Hide bookamrks bar items label text, show on hover. */

.bookmark-item > .toolbarbutton-text {
    margin-top: -1px !important;
}
.bookmark-item:not(:hover):not([open="true"]) > .toolbarbutton-text {
    display: none !important;
}
#PlacesToolbarItems > .bookmark-item:not(:hover):not([open="true"]) > .toolbarbutton-icon[label]:not([label=""]) {
    margin-inline-end: 0px !important;
}