While splitting any stack the "Stack Splitter Bar's Borders are quite "Irregular" and not "Smooth" .

How To Reproduce :

1. Open Minecraft In Any Touch Devices.
2. Play any World.
3. Open Inventory.
4. Hold Any Stack To Split It.

Observation:
If you look carefully then you will notice that the Outer-Most Borders of the Bar are not Smooth amd are broken.

Expected Result:
The Bar must be Well-Finished and Clear/Smooth.

Example in attached images...