On Mobile Web Buttons have two deficiencies.
1. Buttons are missing a font property, so you can't change the font size or face.
2. Buttons do not treat leading spaces in the "title" the same as other platforms. HTML ignores the spaces, so button.title = " Some Text" would be treated as if it were button.title = "Some Text". This is not true on Android or iOS
I'm combining these as I have a fix I'll submit as a pull request.