Create rounded_menupopups.css

chrome/rounded_menupopups.css

@@ -0,0 +1,25 @@
+/* Source file https://github.com/MrOtherGuy/firefox-csshacks/tree/master/chrome/rounded_menupopups.css made available under Mozilla Public License v. 2.0
+See the above repository for updates as well as full license text. */
+
+/* Makes panels, menupopups, urlbar and searchbar rounded */
+
+/* Modify the rounding size here */
+:root{ --uc-menupopup-border-radius: 20px }
+
+panel[type="autocomplete-richlistbox"],
+menupopup,
+.panel-arrowcontent{
+  -moz-appearance: none !important;
+  border-radius: var(--uc-menupopup-border-radius) !important;
+  overflow: -moz-hidden-unscrollable !important;
+}
+
+/* The rounding is also applied to searchbar and urlbar to look consistent */
+searchbar#searchbar,
+#urlbar-background{
+  border-radius: var(--uc-menupopup-border-radius) !important
+}
+
+/* Reposition the panel-arrow  */
+panel[type="arrow"]{ margin-inline-end: calc(-10px - var(--uc-menupopup-border-radius)) !important; }
+.panel-arrow{ margin-inline: var(--uc-menupopup-border-radius) !important; }

html_resources/tagmap.json

@@ -66,6 +66,7 @@
 "overlay_scrollbars.as.css":["scrollbar"],
 "page_action_buttons_on_hover.css":["urlbar","minimal","effect"],
 "pinned_tabs_on_right.css":["tabs"],
+"rounded_menupopups.css":["menu","popup","urlbar"],
 "scrollable_menupopups.css":["scrollbar","popup","menu"],
 "scrollable_urlbar_popup.css":["scrollbar","popup","urlbar"],
 "show_navbar_on_focus_only.css":["urlbar","nav-bar","toolbars","hiding"],

tags.csv

@@ -65,6 +65,7 @@ overlay_menubar.css,menubar
 overlay_scrollbars.as.css,scrollbar
 page_action_buttons_on_hover.css,urlbar,minimal,effect
 pinned_tabs_on_right.css,tabs
+rounded_menupopups.css,menu,popup,urlbar
 scrollable_menupopups.css,scrollbar,popup,menu
 scrollable_urlbar_popup.css,scrollbar,popup,urlbar
 show_navbar_on_focus_only.css,urlbar,nav-bar,toolbars,hiding