CSS3 Media Query - Width of container rather than screen?

[abdelali]

I have not yet seen this question asked on here but I was wondering if anyone knows if it is possible to have a media query based on a container or parent element that was based on it width. The user case for this is when you have a menu that pops in from the left and decreases the size of the main windows container. Here is an example website where you can see the menu pops open but the content on the page cannot change based on its new widthhttp://tympanus.net/Tutorials/FullscreenBookBlock/