Demo: https://codepen.io/emdeoh/pen/oNjgOPy. caniuse.com data: https://caniuse.com/#feat=font-family-system-ui
Definitely needs more testing here, but latest Chrome and Safari support it, Firefox still needs -apple-system
, and legacy Edge/IE (not that we care) require explicit fonts later on.
Fixes #25604 (closed).