Banner directive buttons do not fit full text on smaller screens

On smaller screens, the text for the buttons in the Banner directive do not fit. They should wrap the buttons to allow text to fit. This should be easy using the `flex` class.

Example:

Start by locating the Banner directive and its button markup, then reproduce the layout at a smaller screen size. Use the existing flex class as suggested so the buttons wrap, and verify that all button text fits without overflow on narrow screens.

Written by the indexing model from the issue text.