Based on the research, I found that below is the solution to this problem..
Add the below snippet in style.css
<!-- Fix for the issue - http://issues.appfuse.org/browse/APF-1448 Start --> .navbar
<!-- Fix for the issue - http://issues.appfuse.org/browse/APF-1448 End -->
If anyone has a better solution, then I am interested in it.
Note: This solution has only been tried on Spring MVC + Hibernate version of Appfuse.