I am a user who used to view articles from my mobile. I haven't yet tried to edit wikipedia through it. I have recently opened wikipedia from my mobile phone through Google Chrome browser. I then took the 'view history' page of a random article. I then tried to thank an edit done by a user. In the text that appears ie. 'Publicly send thanks?', I am seeing it in a too low font. I mean the size. So I suggest you to increase the font size for that specific text including the buttons thanks and cancel. All these changes needs to be made only in that confirmation menu.