Calculator App with theme switcher - HTML/CSS/VanillaJS

I've tried to complete this challenge only with "pure" setup, just HTML/CSS/VanillaJS. For the them switcher "Prefers color scheme" was used. Pretty cool stuff. For the calculator functionality i looked up some tricks from the Kevin Powell & Zell Liew from their YouTube videos and added some adjustments to better fit the "brief" and requirements of the challenge. The only thing that i really didn't want to style it's theme switcher at this point, may be will come back for this a little bit later.