Hide bookmark bar labels

chrome/userChrome.css

 /* Remove fullscreen transition animation */
 #navigator-toolbox[fullscreenShouldAnimate] { transition: none !important; }
 
-/* Set favorites icon color to default */
-#urlbar #page-action-buttons #star-button[starred] { fill: currentColor !important; }
-
 /* Enable page action button */
 #urlbar #page-action-buttons #pageActionButton { visibility: unset !important; }
 
-/* Hide reader view button when not active */
-#urlbar #page-action-buttons #reader-mode-button:not([readeractive="true"]) { display: none; }
+/* Set favorites icon color to default */
+#urlbar #page-action-buttons #star-button[starred] { fill: currentColor !important; }
 
 /* Set reader view button color to default */
 #urlbar #page-action-buttons #reader-mode-button[readeractive] > .urlbar-icon { fill: currentColor !important; }
 
+/* Set multifoxContainer button color to default */
+#urlbar #page-action-buttons #userContext-label[value="Default"] + #userContext-indicator,
+#mainPopupSet menuitem.identity-icon-fingerprint[label="Default"] .menu-iconic-icon { fill: currentColor; }
+
+/* Set User Scripts icon to grayscale */
+#appMenu-popup #appMenu-multiView #appMenu-userChromeJS-button .toolbarbutton-icon { filter: contrast(10) grayscale(1) invert(); }
+
+/* Hide reader view button when not active */
+#urlbar #page-action-buttons #reader-mode-button:not([readeractive="true"]) { display: none; }
+
 /* Hide Hover Zoom+ button */
 #urlbar #page-action-buttons #pageAction-urlbar-_92e6fe1c-6e1d-44e1-8bc6-d309e59406af_ { display: none; }
 
 /* Hide default multifoxContainer label */
 #urlbar #page-action-buttons #userContext-label[value="Default"] { display: none; }
 
-/* Set multifoxContainer button color to default */
-#urlbar #page-action-buttons #userContext-label[value="Default"] + #userContext-indicator,
-#mainPopupSet menuitem.identity-icon-fingerprint[label="Default"] .menu-iconic-icon { fill: currentColor; }
-
 /* Shrink bookmark separators */
 #PlacesToolbarItems > toolbarseparator::before {
-	filter: opacity(0.3);
+	filter: opacity(0.3) !important;
 	height: 80%;
 	margin: auto;
 }
 
-/* Set User Scripts icon to grayscale */
-#appMenu-popup #appMenu-multiView #appMenu-userChromeJS-button .toolbarbutton-icon { filter: contrast(10) grayscale(1) invert(); }
+/* Remove bookmark bar text (and extra gap) */
+#personal-bookmarks .bookmark-item > .toolbarbutton-text {
+	max-width: 0;
+}
+
+#personal-bookmarks .bookmark-item > .toolbarbutton-icon:not([label=""], [type="menu"]) {
+	margin-inline-end: revert !important;
+}
+
+/* Animate bookmark bar text on hover/focus */
+#personal-bookmarks .bookmark-item:is(:hover, :focus, :active) > .toolbarbutton-text {
+	max-width: inherit;
+	transition: max-width 0.5s ease-out;
+}
+
+#personal-bookmarks .bookmark-item:is(:hover, :focus, :active) > .toolbarbutton-icon:not([label=""], [type="menu"]) {
+	margin-inline-end: inherit !important;
+}
+
+/* Always show bookbar bar text for folders */
+#personal-bookmarks .bookmark-item > .toolbarbutton-icon[type="menu"] + .toolbarbutton-text {
+	max-width: none;
+}