diff --git a/theme/nchyn_grey.html b/theme/nchyn_grey.html
index b8a3e85..c9c05bf 100644
--- a/theme/nchyn_grey.html
+++ b/theme/nchyn_grey.html
@@ -45,7 +45,9 @@
     background-image: url('<!--BackgroundUrl-->');
     background-size: cover;
     background-repeat: no-repeat;
-    height: 100%;
+    background-attachment: fixed;
+    background-position: center;
+    height: 100vh;
     <!--BackgroundEnd-->
 }