Use KDE's Breeze dark and light cursors on Cookie Clicker!
Just subscribe to https://steamcommunity.com/sharedfiles/filedetails/?id=2700647149
Just add the following code to the extension:
https://github.com/raw/agostaxyz/cookie-clicker-breeze-cursor/main/ccmm.js
It's browser specific so no tutorial, but this is the code you need:
Game.Loader.Replace('cursor.png',src="https://github.com/raw/agostaxyz/cookie-clicker-breeze-cursor/main/breeze-cursorMod/cursor.png");