Bug 1842089 - Adapt our menuseparator styling after bug 1766470. r=freaktechnik

Differential Revision: https://phabricator.services.mozilla.com/D182971

--HG--
extra : moz-landing-system : lando

mail/themes/shared/mail/EditorDialog.css

@@ -273,14 +273,6 @@ tree.list {
   min-height: 200px;
 }
 
-#AddJSEAttributeNameList > menupopup > menuseparator,
-#AddHTMLAttributeNameInput > menupopup > menuseparator {
-  appearance: none;
-  margin-block: 3px;
-  padding-block: 0;
-  border-top-color: #d7d7d7;
-}
-
 html|fieldset {
   margin: 1em 3px 3px 3px;
   padding: 3px 0 6px;

mail/themes/shared/mail/accountManage.css

@@ -62,11 +62,7 @@ fieldset:last-of-type {
 }
 
 .openpgp-more-btn > menupopup > menuseparator {
-  appearance: none;
-  margin: 0;
-  padding: 0;
-  border-top: 1px solid var(--in-content-box-border-color);
-  border-bottom: none;
+  padding-inline: 8px;
 }
 
 #archiveHierarchyButton,

mail/themes/shared/mail/accountManager.css

@@ -235,11 +235,7 @@ body {
 }
 
 #accountActionsDropdown > menuseparator {
-  appearance: none;
-  margin: 0;
-  padding: 0;
-  border-top: 1px solid var(--in-content-box-border-color);
-  border-bottom: none;
+  padding-inline: 8px;
 }
 
 #accountActionsButton > .button-box > .button-menu-dropmarker {

mail/themes/shared/mail/contextMenu.css

@@ -126,12 +126,7 @@ menubar:not(:-moz-lwtheme) > menu menupopup >
 }
 
 menupopup > menuseparator {
-  appearance: none !important;
-  min-height: 0;
-  border-top: 1px solid var(--panel-separator-color);
-  border-bottom: none;
-  margin: 4px 8px;
-  padding: 0;
+  padding-inline: 8px;
 }
 
 #ContentSelectDropdown > menupopup {

mail/themes/shared/mail/themeableDialog.css

@@ -378,11 +378,7 @@ menulist[is="menulist-editable"][editable="true"]::part(text-input):focus {
 
 button menupopup menuseparator,
 menulist menupopup menuseparator {
-  appearance: none;
-  margin: 2px 0;
-  padding: 0;
-  border-top: 1px solid var(--box-border-color);
-  border-bottom: none;
+  padding-inline: 8px;
 }
 
 :root[lwt-tree] .autocomplete-richlistbox {