sidebars covering header

If you’re not using a Child Theme, and if the theme doesn’t have a section for CSS modifications then do the following:

1. Install this Custom CSS Manager plugin http://wordpress.org/plugins/custom-css-manager-plugin
2. use its “CSS Code” section of the dashboard to hold your CSS modifications:
3. (put this code in)

   
   .right-sidebar-wrapper {
       z-index: 0;
   }
   

4. Save

Alternatively use your Child Theme style.css file to hold your CSS modifications