[ionic 4] ion-range slider to programatically change all element sizes globally

What I want to achieve is the following:

Have a settings page where there is an ion-range slider that allows the user to change the size of all elements inside of the app globally. Meaning the entire app will become bigger and thus easier to read for people with bad eyesight.

Meaning if the slider is on the right the size of all elements become bigger.

I’ve tried doing this in ionic 3 with font-size on the html element, which worked there, however when I try to do this in ionic 4 for some reason all the elements stay the same size.

Does this have something to do with the shadow dom?

How would I be able to achieve this same effect in ionic 4?

Please let me know what I can do to achieve this.

Yeah, Im not 100% sure this is possible with v4.
Not 100% to do with shadowDOM, just how we structure the html.
We set the sizes directly on the elements themselves.

So it’s not really possible to just adjust them based on a range slider.
There is some hope though, it just involves using apple’s system fonts to hook into they accessibility settings.
But that is not what you’re looking for at the moment.

Would it be possible to override some of these elements to use percentage or em based font sizes? That should be enough to be able to set a base value on the body or html tag that would scale all the elements that are using such values.

Are there any plans in the future for adding this?
Do you accept pull requests from community members?

Thank you for your answer.