Hi! Just noticed this now as I was looking into some great feedback we got about this in Support.
This is too late to answer your question, but hopefully helps others. A bit simplified, but
line-height is based normally on the element's
font-size. ** Ideally, yes, this should've been covered in the course, or at least a hint given in the description (which I may open up an improvement issue for later since as far as I can tell this is both tricky and not covered in this course).
Since in this case the effective px of the
font-size is 50px, and you want the
line-height to be 30px but in em values, 30/50 is equivalent here to the em value, which is
** For more details, including how inheritance affects
Note it's a bit better to actually not use
ems, and just leave it as a number (not what the question asked for, so that isn't accepted, but if doing this in the real world).
update: Have opened an issue to add an explanation of how to calculate
line-height to the description.
update #2: Took quite a while as it's an older, uniquely set-up course, but the course is set up in dev. A clarification should be simple, and then I'll try a deploy out today or tomorrow.
update #3: Clarified in challenge, and also accepted
0.6 as unitless is now better.