Apply font-family to more ‘select’ items and ‘input’

Regarding #1990.

@nilshoerrmann, I've removed the font declaration from `.apply select` and instead added selectors to what seems to be the main `font-family` block.

I also changed `input[type="submit"]` to `input`. I'm not 100% sure about this, but I'm not aware of a reason to only select submit inputs here and things look okay for me. Please check. Thanks.