Image doesnt expand entire width on high resolutions

Monday, May 5, 2014

I have a website which is using the Golden Grid System. You can see my site here

On low resolutions as in the screenshot below you can see the top two images span equally and they look correct.

enter image description here

But below if you look if im over lets say 1980x1080 the top two images retain there size and dont expand the entire width equally.

enter image description here

I have my code here but I have no idea what i am doing wrong.