Bug 1734226 - Reset default styles for search one offs. r=desktop-theme-reviewers,Itiel

Differential Revision: https://phabricator.services.mozilla.com/D127623

browser/themes/shared/searchbar.inc.css

@@ -67,6 +67,8 @@
 .searchbar-engine-one-off-item {
   appearance: none;
   display: inline-block;
+  background-color: transparent;
+  border: none;
   min-width: 32px;
   height: 32px;
   margin-inline-end: 8px;

browser/themes/windows/searchbar.css

@@ -4,11 +4,11 @@
 
 %include ../shared/searchbar.inc.css
 
-.searchbar-engine-one-off-item:-moz-focusring {
+.searchbar-engine-one-off-item:focus-visible {
   outline: none;
 }
 
-@media (-moz-proton) and (-moz-os-version: windows-win10) {
+@media (-moz-os-version: windows-win10) {
   #PopupSearchAutoComplete {
     /* A border is necessary because the shadow is bottom-right */
     border-color: var(--menu-border-color);