Can responsive columns be added?

Is there a way to make the columns in the theme a little more, well, responsive?

If I view the theme authors website on a mobile device, the “features” column stay three abreast even on the smaller screen device, which makes it awkward to read.

Is there a way (in the CSS) to get these columns to retain a minimum width and “shuffle” so instead of staying three columns, they reposition beneath each other?

Thank you.