--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -776,20 +776,16 @@ html|input.urlbar-input[textoverflow]:no
 #identity-icon-country-label {
   direction: ltr;
 }
 
 #identity-box.verifiedIdentity > #identity-icon-labels > #identity-icon-label {
   margin-inline-end: 0.25em !important;
 }
 
-#main-window[customizing] :-moz-any(#urlbar, .searchbar-textbox) > .urlbar-textbox-container > .textbox-input-box {
-  visibility: hidden;
-}
-
 /* Flexible spacer sizing (matching url bar) */
 toolbarpaletteitem[place=toolbar][id^=wrapper-customizableui-special-spring],
 toolbarspring {
   -moz-box-flex: 1;
   min-width: 28px;
   max-width: 112px;
 }
 

--- a/browser/themes/shared/urlbar-searchbar.inc.css
+++ b/browser/themes/shared/urlbar-searchbar.inc.css
@@ -64,16 +64,20 @@
   min-height: 32px;
 }
 
 :root[chromehidden~="toolbar"] #urlbar {
   /* Remove excess space between the address bar and the menu button in popups. */
   margin-inline-end: 0;
 }
 
+:root[customizing] .urlbar-input-box {
+  visibility: hidden;
+}
+
 #urlbar-container {
   -moz-box-align: center;
 }
 
 #urlbar-search-splitter {
   /* The splitter width should equal the location and search bars' combined
      neighboring margin and border width. */
   min-width: 12px;