explorer: does the celestial armor require a medium armor domain?

TL; DR: Does the celestial armor require a medium armor domain?

I found the Celestial Armor that said it is a medium Chainmail + 3 armor, and that it is light enough to be considered as a light armor.

But does it work like a Chainmail made of Celestial Mithral, ​​which then makes the armor light enough to be considered a light armor, but still requires a medium armor domain?