So Im trying to make an off canvas menu using flexbox. Basically, I have a row of 3 items (that have the stretch property so they go to the bottom). Here is a screenshot of a drawing for reference: http://prntscr.com/79hrf2. I know how to create an off-canvas menu that upon pusing the menu button causes the content to be pushed to the left to reveal the menu underneath. BUT, what Id like to do, is instead of pushing all the content to the left (which would push the left sidebar off the screen) is to have the right sidebar come in and the other 2 parts flex and shrink to accomodate it.