diff -r 000000000000 -r 6474c204b198 content/xml/document/resources/XMLMonoPrint.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/xml/document/resources/XMLMonoPrint.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+@charset "UTF-8";
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+@import url("chrome://global/content/xml/XMLPrettyPrint.css");
+
+#top > .expander-open {
+  font-family: monospace;
+  white-space: pre;
+}