You use one master page and everything you want to change from tablet to mobile should happen there.
If you reduce your header height, do so to your needs. Place all elements you need in your header, hide other elements (right click - hide in breakpoint - hide in other breakpoints is what you need here maybe), which you might have not enough space for.
Does this help for the beginning?
Each page could only have one master.
Does this help?
Thank you , this does help a great deal! I will be trying your suggestion out this evening.
Let me know, you could open a new thread with newer questions or stay here.
We have great forum members to support you with almost everything , except food and coffee .
You could do all settings of size and place with on element each.
Even one text element for all breakpoints works fine.
There´s one exception, if you group elements (only with fluid width breakpoints), these should be copied and hided in all other breakpoints. Groups, once they´re set, want to show on all breakpoints and you have to deny that.
Keep on and best Regards,