I am trying to use CSS Columns to show submenu items stacked vertically in horizontal stacks/columns. I would also like to have a fallback of a scrolling menu if the browser doesn’t support css columns. However it seems that CSS Columns are expanding beyond the containing positioned element.

CodePen : http://codepen.io/anon/pen/dKAJF

Stack Overflow : http://stackoverflow.com/questions/26244353/css-columns-blowing-out-of-positioned-container-element