Issue #1663174 by Albert Volkman, oresh: Clean up system main css.

core/modules/system/system.maintenance.css

 /**
  * Update styles
  */
-#update-results {
+.update-results {
   margin-top: 3em;
   padding: 0.25em;
   border: 1px solid #ccc;
   background: #eee;
   font-size: smaller;
 }
-#update-results h2 {
+.update-results h2 {
   margin-top: 0.25em;
 }
-#update-results h4 {
+.update-results h4 {
   margin-bottom: 0.25em;
 }
-#update-results li.none {
+.update-results .none {
   color: #888;
   font-style: italic;
 }
-#update-results li.failure strong {
+.update-results .failure strong {
   color: #b63300;
 }
 
@@ -41,12 +41,12 @@
 }
 
 #edit-connection-settings-change-connection-type {
-  margin: 2.6em 0.5em 0em 1em;
+  margin: 2.6em 0.5em 0 1em;
 }
 
 /**
  * Installation task list
  */
-ol.task-list li.active {
+.task-list li.active {
   font-weight: bold;
 }

core/update.php

@@ -250,7 +250,7 @@ function update_results_page() {
       }
     }
     if ($all_messages) {
-      $output .= '<div id="update-results"><h2>The following updates returned messages</h2>';
+      $output .= '<div class="update-results"><h2>The following updates returned messages</h2>';
       $output .= $all_messages;
       $output .= '</div>';
     }