This bug is observed in the Graph widget.

Steps to reproduce:

1. Create 2 templates
2. For each template create an item called Available memory.
3. Assign both templates to one host.
4. Open the widget and add the host pattern, item patterns.
5. Hover over any data point.

When hovering the graph, the hover info displays incorrectly. The background is not full filled and mixed text, making the information hard to read. This bug affects the clarity and usability.