Font size adjust provides a simple way to conform all the fonts used in a string of text to be the same visual size — so every character in
1.4rem
-sized text, for example, has the same x-height — or cap height,ch
width,ic
width, oric
height. The two value syntax allows you to choose which measurement to conform.
This can be useful when you're mixing two fonts within a sentence, e.g. a monospace font for code and a regular font for copy.
https://developer.mozilla.org/en-US/docs/Web/CSS/font-size-adjust