--- a/browser/themes/shared/urlbar-searchbar.inc.css
+++ b/browser/themes/shared/urlbar-searchbar.inc.css
@@ -43,16 +43,21 @@
   margin-bottom: 3px;
 }
 
 :root[uidensity=touch] #urlbar,
 :root[uidensity=touch] .searchbar-textbox {
   min-height: 32px;
 }
 
+:root[chromehidden~="toolbar"] #urlbar {
+  /* Remove excess space between the address bar and the menu button in popups. */
+  margin-inline-end: 0;
+}
+
 #urlbar-container {
   -moz-box-align: center;
 }
 
 .urlbar-input-box,
 .searchbar-textbox > .autocomplete-textbox-container > .textbox-input-box {
   margin: 0;
 }