Firefox Input Background Image

Has anyone noticed this?

When you put a background-image into an input field in Firefox Mac/Win, the input borders get distorted (it’s darker…)

I don’t have a fix for it, actually, I am not even sure it’s broken. Also, the blue highlight the input field gets when it is in focus, does not appear when you add background-image to an input field.

I think that’s a very strange default behavior.