Fixing page to screen

My app is focused on mobile use.

For that I would like the page to be fixed to the screen size so that no scrolling or gaps appear.

Do you know how I can ensure that?

Thank you

You need to install plugin for responsive viewport height.
Here is video on this topic Toolit Kit - Hero Sizing Element Video Tutorial

Thank you.
I wached the tutorial and it seem to help with my task. I will test it after some sleep.