So I am currently working on an application that runs on top of the customers page inside its own iframe. 

Application works in backbone and everything else except the initialization of the iframe is done inside the iframe. Initialization happens with a small javascript snippet that the client will copy to their footer.

The problem I'm currently having is that I have to inject a CSS file to the parent site in order to style my iframe correctly when it's rendered and I really don't think that I should tamper with clients page at all since CSS might have some conflicts in it.

Is there any better way to style the iframe than the current way of doing it?