Display issues with hexagon buttons in class management screen

[TomlDev]

See the screenshots:

Menu overflow:

No buttons but the bar does not disappear:

Additionally changed:

Wrong indent (compared to security page):

LoadingIndicator has transparent background but a white border what looks strange when there is content behind:

https://github.com/user-attachments/assets/b52273a6-db1a-42e0-86bf-a34306e4d038