What problem does this solve or what need does it fill?

Could help in order to reproduce web default behaviour easily

What solution would you like?

Probably something as simple as passing an "BoxSizing" enum value to Style

What alternative(s) have you considered?

Made some tests but these were unfortunately inconclusive.

Additional context

If there is already a siimilar feature supported, then I am sorry, but I feel like I've done the research work through issues/ code