Responds font getting smaller and smaller

Hello,

Can’t understand why, but on each repsond line in comment section coment-font is getting smaller and smaller (see pic https://www.dropbox.com/s/jwtqcbok6oht8iw/%D0%A1%D0%BD%D0%B8%D0%BC%D0%BE%D0%BA%20%D1%8D%D0%BA%D1%80%D0%B0%D0%BD%D0%B0%202015-08-04%20%D0%B2%2017.44.13.png?dl=0 ).

Using Hemingway skin.

Thanks in advance!