How to list stores with responsive columns

Thank you for the great plugin. So far we are liking it very much.

I’d like to list our stores below the map. However we are finding that the default view of a list causes the site visitor to scroll way too much. We’d like to change to a columnar view (maybe 3 columns) when the user is on a computer but have the listing change to a single column on a phone.

I found some css customizations that allowed for changing the view to 2 or 3 columns but when I do that, the display looks great on a PC but horrible on the phone.

I used the css customization listed at this following link for the current columns.
https://wordpress.org/support/topic/store-listings-in-multiple-columns-below-map?replies=5

It seems that this is a frequently asked question but I’m having a hard time pinning down the solution.

We are using WP Store Locator 2.2.2 with WordPress 4.5.3

Thanks for your help in advance.
Andy

https://wordpress.org/plugins/wp-store-locator/