Bug 1896330 - Stop using the plain class on unknownContentType.xhtml. r=dao,desktop-theme-reviewers

And remove it from global-shared.css

Differential Revision: https://phabricator.services.mozilla.com/D210151

toolkit/mozapps/downloads/content/unknownContentType.xhtml

@@ -39,15 +39,15 @@
     <hbox align="start" class="small-indent">
       <image id="contentTypeImage"/>
       <vbox flex="1">
-        <description id="location" class="plain" crop="start" flex="1"/>
+        <description id="location" crop="start" flex="1"/>
         <separator class="thin"/>
         <hbox align="center">
           <label id="whichIs" data-l10n-id="unknowncontenttype-which-is"/>
-          <html:input id="type" class="plain" readonly="readonly" noinitialfocus="true"/>
+          <html:input id="type" readonly="readonly" noinitialfocus="true"/>
         </hbox>
         <hbox align="center">
           <label data-l10n-id="unknowncontenttype-from" id="from"/>
-          <description id="source" class="plain" crop="start" flex="1"/>
+          <description id="source" crop="start" flex="1"/>
         </hbox>
       </vbox>
     </hbox>

toolkit/themes/shared/downloads/unknownContentType.css

@@ -13,9 +13,14 @@
 }
 
 #type {
+  appearance: none;
   flex: 1;
   background-color: transparent;
   color: inherit;
+  border: 0;
+  margin: 0;
+  padding: 0;
+  outline-offset: 0;
 }
 
 #from {
@@ -43,5 +48,6 @@
 
 #source,
 #location {
+  margin: 0;
   contain: inline-size;
 }

toolkit/themes/shared/global-shared.css

@@ -117,13 +117,6 @@
 
 /* General styles */
 
-.plain {
-  appearance: none;
-  margin: 0 !important;
-  border: none;
-  padding: 0;
-}
-
 moz-input-box,
 html|input {
   min-width: 0;