- whatever font size is set on
html is what rem is relative to
- percentages in font-size are equivalent to using
em/100
- except on
html, because there’s no parent, so it refers to the browser font scaling, which is 16px by default on major browsers, but can be scaled to be 9 <= x <= 72 in settings
- browser zooming additively scales everything, on top of browser font scaling
- almost all websites do not respect browser scaling, because they set a hard-coded font-size on
html, or use px which opts out of scaling entirely
- when browser scaling is ignored, there’s no a11y reason to use
rem over px
- jwc article