RT Modern UI
(repost) official

this is a discontinued minecraft UI pack. instead, check fluent ui.
also, reposted cuz i lost the account that it was posted on
How to setup
W I N D O W S

once installed on your Windows PC, Go to file explorer, Click on the .zip file one time, then do CTRL+C (or right click > Copy) for windows 11, its (right click> Show more options > Copy) after copying, do WIN + R then type in the box %appdata% and go to the folder .Minecraft and go to the folder resourcepacks and paste the .zip file. thats all!

M A C O S

1. If needed use “Archive Utility” or the “Unarchiver” to make files usable on the mac
2. click In Finder and File on the top of the screen. On the drop down menu it should say “Go to folder”
3. Paste ~/Library/Application Support/minecraft/resourcepacks
4. now drag the pack.
5. Then launch Minecraft and go to Options -> Resource Packs
6. thats all!