I need to build a responsive site with a menu system that can go 3 levels. I'm guessing that drop-downs are out of the question. Top level would be probably about 7 links, second level maximum 8 links, third tier maximum 6 links. I want the site to also work on mobile devices and also to be accessible. I have a fair amount of experience with responsive design, but with the accessibility and mobile accessible experience I could really use some good advice.

I'm having a difficult time strategizing how to do this. Does anyone have any ideas?