content class is still grid 9 even though sidebar is display:none.

I am using the media queries to hide and show blocks depending on the screen width. The problem I cam across is trying to place a block in sidebar first. I use display:none in my global css, and then show it in my narrow css. the problem is that even if sidebar first is display:none the content gets the class of grid-9 instead of grid-12. Any help appreciated! =)