The bottom of the property panel is transparent
Problem/Motivation
When setting up a test model with all available bpmn elements i've notice that the bottom of the property panel is actually transparent
Being transparent wouldnt't be a problem but due to the fact that there is the left border of the property panel, being the handle for resizing, spanning across more or less the whole available vertical viewport it looks kind of unintended and off.
Steps to reproduce
1. create a new model
2. create a start event
3. create a task
4. connect the two element with an association (not sure if association or sequenceflow is the right term for the connection in that context in bpmn)
5. active the hand tool
6. drag parts of the start event/task combo underneath the bottom of the property pane
Proposed resolution
make the bottom of the property panel opaque
Related issue: Issue #3238206