Make changes to both pages

I started creating my app for pc, but now i also want for it to work on mobile.
I created a new copy of the pc index for a index mobile, but now when i chage something, it only changes to that index. Is there a way to “link” the changes on both index?

Instead of creating 2 different pages / versions of your app for both computer & mobile use, I would highly recommend instead creating 1 version using the Responsive engine. This will give you control over the spacing/layout of the app depending on the user’s browser and/or monitor size.