diff --git a/source/Ox.UI/css/theme.css b/source/Ox.UI/css/theme.css
index 7abdf260..1f1a08a4 100644
--- a/source/Ox.UI/css/theme.css
+++ b/source/Ox.UI/css/theme.css
@@ -1,4 +1,7 @@
-body.$themeClass {
+body.$themeClass,
+body.$themeClass:fullscreen,
+body.$themeClass:-moz-full-screen,
+body.$themeClass:-webkit-full-screen {
     background-color: $bodyBackground;
 }
 .$themeClass a {