Casper Title and Text fonts

I was wondering what is the name of the default font used in Casper for the title and the text?
I read modern sanf-serif for the title and Elegant serif for the text, but that’s very generic.

Casper uses your device system font, so it will be different depending on what device you use. For Apple devices, the system font is called San Francisco

Thanks for the answer John. I see on the Apple page there are many San Francisco: Pro, Compact, Mono, Arabic. Which is the one?