Steps to reproduce:

1. Create a new project
2. Install the Entities package
3. Create a new Scene
4. Create and add a SubScene to an Empty GameObject
5. Attach the new scene to the "Scene Asset" in the Inspector
6. Open the Window > Entities > Systems window
7. Select any System in the window
8. Grab the separator on the right side to resize the section (resize the System window if you can't see the separator)
9. Drag the separator completely to the left
10. Observe the Systems window

Actual results: The section can be moved completely to the left (background has a size limit set, while the content does not)

Expected results: The size of the content in the section is limited, together with the background

Reproducible with versions: 6.5.0 (6000.5.0b4, 6000.6.0a3)

Can’t test with versions: 1.4.5 (6000.0.73f1, 6000.3.13f1), 6.4.0 (6000.4.3f1) (No section on the right)

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Sometimes the section is not visible. To make it visible, resize the right side of the Systems window to make it appear - this is part of the described problem