NOW IN 1.21+ (26.1+ due in november with custom music disc!)
Thanks for your support!
This Resource pack has GUI (Including In-game, title screen, pause menu and Hotbar!) To see how it look like check the images/screenshot page to find out.This project has more feature to add such as Custom music to replace the Minecraft version, fonts and plenty more.This resource pack is only for 1.20.1. I am trying to test out different version to see if it works. (Updates are not that fast as finding different or creating GUI are hard)