Q:

CSS - Where has this empty space come from?

I am modifying a responsive WordPress website. 
It uses media queries to display at different resolutions depending on the users screen size. Everything displays correctly until we size down to the smallest screen which has a max width of 750px. This is determined by the responsive.css file.
When at this size, there appears to be a blank space to the right side of the website. I have literally spent 2 hours trial and error to resolve this but have had no luck.

A:

The issue is at .slider_arrow_spacer { width: 620px; } line 959 global.css.
I had to do this little trick to find it, because it was so thin you could not see it:
$("*").each(function(){ if($(this).width() > 507) { console.log($(this)); } });
It loops all elements looking for some element larger than 508px (which was supposed to be the wider to fit inside your wrapper).

