Button Behavior on Mobile Devices

On one of my sites https://tinyhousereport.com which uses a child theme of Twenty Twelve and I’m trying to duplicate the Read More button behavior I have used on another site of mine https://personaltrainer-hq.com/blog/

I copied the css line-for-line for the Read More button css from https://personaltrainer-hq.com/blog/ and dropped it into the style.css for https://tinyhousereport.com.

The button behave very differently on mobile devices and I cannot locate the culprit.

I would appreciate any and all guidance.