Discussing making a new way to measure the distance for letter-spacing, word-spacing, text-underline-offset, etc as a % of the current font size for the text you are on. Yes? Another option might be to add a new unit. (Can't use ems. Too late because inheritance & web compat.)

Clarifying for voters: the important part here is that it needs to *inherit*, but calculate based on each element's own font-size. The 'em' problem is that it's calculated based on the first element's font-size, and then inherits as a fixed px value to descendants.

Don't percentages for `line-height` have the same problem? Wouldn't it be confusing if percentages for `line-height` and `letter-spacing` etc. will be inherited differently?

Yes, line-height %s are bad. (They're *completely identical* to just using em; I have no idea why they were specified this way.) The confusion aspect is definitely on our mind, but it's contrasted with %s working in the desired way *everywhere else* in CSS.

I assume Tab, it's too late to change how line-height in %s works. That's too bad. It'd be nice to change it to inherit / work like what we are proposing for everything else. #timemachine

Yeah, that dates back to *at least* CSS2, possibly before. Frozen now.