AMP & CSS @font-face error

Hello,

We are trying to make our website compatible with AMP, however we are getting an error in the GridKit stylesheet because of the way @font-face is used. The information is at the url: https://www.ampproject.org/docs/fundamentals/spec#custom-fonts

I don’t see a way in the settings to disable this. Is there anyway that we can remove this or modify it through custom css?

Thank you