I have styled the ‘Subscribe’ button but when viewing on a mobile (iPhone 6) the subscribe button has lost all of the custom CSS. Also, when I view on my Mac at the same resolution as the iPhone the button appears as it should.
Probably the button is not loosing the style but getting a specific style for low width devices. Those rules could be inside your theme css. Or your rules are targeted only to large screen and not applyes to the smaller ones.
Thanks for your reply. I the problem is that I cannot duplicate the issue on my Mac to take a look at the problem, it only seems to be visible on my iPhone using Safari. Any ideas?