Merge pull request #478 from Jeffiy/master

fix login page CSS

notebook/static/auth/css/override.css

@@ -3,6 +3,6 @@ This is only required when different pages style the same element differently. T
 a hack to deal with our current css styles and no new styling should be added in this file.*/
 
 #ipython-main-app {
-    margin: 50px auto;
+    padding-top: 50px;
     text-align: center;
 }