Automatic adjustment of font-size on math tag?

This is a follow-up of https://github.com/mathml-refresh/mathml/issues/37

With the rule math { font-family: math; }, the default behavior is to use a math font instead of inheriting the font from the parent that (likely) is not designed for math layout and would result in poor rendering.

The font-size is inherited, but since the surrounded text and the math formula uses two different font families, the actual size of glyphs is different.

MathJax has a configuration option to try and workaround this:
https://docs.mathjax.org/en/latest/options/output/index.html#output-matchfontheight

Do we want to enhance font-size with a property value that automatically perform this kind of font-size adjustment when changing the font-family?

Or do we want to add some special adjustment for "font-family: math" (when I checked WebKit and Chromium code, it seems they do something for font-family: monospace but not sure whether that's specified by CSS).

Or is it something that should be performed by a polyfill?

Or do we just don't care, and we should let people setup their CSS themselves?

(Note: of course, the ideal situation is when one uses a text font with its math companion, like STIX Two for the text and STIX Two Math for the math, see https://fred-wang.github.io/MathFonts/ ; this issue is about what we should do for the default)

Start by reading issue #37 and the linked MathJax matchFontHeight documentation. Compare the options described here: a new font-size value, special handling for font-family: math, a polyfill, or no built-in adjustment. Done means the project has a decided direction for default math font-size behavior.