It does not work, checked on chrome and mozilla,
pls check the codepen link: https://codepen.io/s827/pen/ZEoXJXm
when replaced percentage with vw or px, code works, but not with %:
I thought you meant that you were not able to pass the challenge.
In codepen, you have to set the body’s height to 100vw to make this work the same as in fcc.
fCC has some sort of “iframe” in which it previews your code and so that makes things work differently slightly here than elsewhere.