add diff styles to application.css

public/stylesheets/application.css

@@ -770,16 +770,19 @@ div.autocomplete ul li span.informal {
 #related_issue_candidates ul li {width: 500px;}
 
 /***** Diff *****/
-.diff_out { background: #fcc; }
-.diff_out span { background: #faa; }
-.diff_in { background: #cfc; }
-.diff_in span { background: #afa; }
+img.diff, div.diff, table.diff, blockquote.diff, address.diff, h1.diff, h2.diff, h3.diff, h4.diff, h5.diff, h6.diff, hr.diff, p.diff, pre.diff, table.diff, ul.diff, ol.diff {
+  padding: 3px;
+  margin: 3px;
+}
+.diff.diff_out    { background: #fcc;}
+.diff.diff_in     { background: #cfc;}
+.diff.diff_change { background: #ffc;}
 
 .text-diff {
-padding: 1em;
-background-color:#f6f6f6;
-color:#505050;
-border: 1px solid #e4e4e4;
+  padding: 1em;
+  background-color:#f6f6f6;
+  color:#505050;
+  border: 1px solid #e4e4e4;
 }
 
 /***** Wiki *****/