I'm building a responsive site http://www.ashleykirk.ca/AB4/

I don't understand why my gray sidebar box is not sitting directly under the yellow sidebar box. It seems to be lined up with the top of my last "home-feature". I could probably fix this if I wrap all of my "home-feature" boxes in a div, but I'm not sure that's the right way to do it. What is the best way to do this?

Also, I don't want to change the HTML order because it is the order I want when stacked for mobile.