Headers

font: -apple-system-headline;

This is a headline that is quite long with a lot of letters and words

font: -apple-system-subheadline;

This is a subheadline that is also quite long with many characters

font: -apple-system-short-headline;

Short headline

font: -apple-system-short-subheadline;

Short subheadline

Body Copy

font: -apple-system-body;

You can say, "I love you," in Helvetica. And you can say it with Helvetica Extra Light if you want to be really fancy. Or you can say it with the Extra Bold if it's really intensive and passionate, you know, and it might work.

- Robert Bringhurst

font: -apple-system-tall-body;

Space in typography is like time in music. It is infinitely divisible, but a few proportional intervals can be much more useful than a limitless choice of arbitrary quantities.

- Robert Bringhurst

font: -apple-system-short-body;

Typographic style is founded not on any one technology of typesetting or printing, but on the primitive yet subtle craft of writing.

- Robert Bringhurst