Unsolved resizable layout based on default font size

[randsfjorden]

Dear Qt-Community,
I wrote a qml-app with a completely resizable layout. The size of the layout is based on the default size of the default qml-font. What I'd like to know is, what the default qml-font-size is based on. I noticed, that when I increase the size of texts and elements in Windows (can increase it to 125% or 150%), the default qml-font-size doesn't change. A QWidgets-application resizes according to this value, as all windows widgets do. I noticed the same on Android.

Is there a way to find out the system's default font size in qml? With that value, I could make the layout adapt exactly to the size the user wants in all other applications as well. I think that is maybe something other developers could need, too.

Greetings - and thank you very much in advance!