I had a look in the first commit of the repo for the Dawn theme I initialised. I’ve actually found the ‘–viewport-height’ being set in the MenuDrawer class in global.js. It’s checking if the platform is an iPhone, and then setting the property for stylesheets to reference. It’s actually pretty neat.
My confusion must have been when I added the function myself (not knowing it already catered for it), and then seeing references to the property afterwards and being confused as parts of the base stylesheet were referencing the exact property I was setting, therefore getting confused if I actually did add the function myself. lol.
Thanks for the reply anyway.