base takes care of many mobile cases automatically. marginN classes reset and colN classes adjust to 100% width when viewed in mobile to promote a flat linear list. There are cases however where you want to manage the presentation of items in a mobile context on your own. The following classes can help with this.
When added to a parent container any nested colN class retains its original width and overrides the 100% that happens by default. This is particularily useful when there's small number of tabs in a navigation interface.