Describe the bug
In BdN, both text and annotation panel have a grey background after a certain point. The border between the text and annotation panel disappears after that point.

To Reproduce
Steps to reproduce the behavior:

1. Go to BdN Teller , open item "Vorrede" in "Auflage A" or any other item in any "Auflagen"
2. Open the annotation panel
3. Scroll down until you see grey background in both text and annotation panel (see screenshot)
4. Close the annotation panel, the grey background remains.

Expected behavior
The background for annotation panel is grey, for the text - white. The border between text and annotation panel stays until the bottom.