Full Screen Background for Header 1 not working on mac

Hi there, we are using a full screen background image on the Header 1 Position in your template. It all looks great on everything except for macs wich display it with a white border. How can we fix this issue?

Hi

Actually it's displayed correctly. This template was designed like that as You can see on our demo: https://demo.gavick.com/joomla25/john/ Unfortunately changes to the template's code to use full width for header would be extensive and I'm afraid beyond our support.