https://github.com/jonathantneal/system-font-css/blob/gh-pages/README.md

https://medium.design/system-shock-6b1dc6d6596f?gi=90078e194544

https://furbo.org/2018/03/28/system-fonts-in-css/

https://css-tricks.com/snippets/css/system-font-stack/

https://devhints.io/css-system-font-stack

https://asciidoctor.org/docs/asciidoc-writers-guide/