What you're describing is already dealt with by mobile applications, and could easily be added to a PowerPoint/Publisher type app. You wouldn't have to use a fixed viewport.

Here is a screenshot of Android Studio using a point-and-click layout editor to create responsive design, with no manual editing of code: https://developer.android.com/static/images/screens_support/... https://developer.android.com/guide/topics/large-screens/sup... It's very reminiscent of Visual Basic.