Remove white space behind and to left of header in customizr

I have searched all of the forum documentation and tired different code snippets, and cannot find a solution to the above issue that I’ve encountered in my Customizr theme. I need to remove white space behind and to left of header in Customizr. The header box does not quite extend exactly to the left side of the screen, leaving about an 1/8″ white space between the left side of the header and the edge of the screen. This does not occur in the footer – it is flush with the edge of the page/screen. Please advise.