@Ranny_Bergamotte this is awesome! I use Vivaldi often and I'm looking forward to trying the theme. It seems like it's taking a while to approve though; I've been checking on it since you first posted this and I still get this access denied page with the little fireball guy:
I just circled back and installed it with the .zip file you linked. I didn't know what I was getting myself into, but honestly it couldn't have been simpler. Nice one Ranny!