how to remove black title bar in browser widget when showing a pdf?

[Tiemo Hollmann TB]

Hello,

LC 8.1.3, Windows 10: When I am displaying a pdf (local or web) in the
browser widget, there is a black title bar on top of the pdf, which occupies
the top 45 pixels of the browser widget. When hovering over the widget, the
name of the pdf is shown within this black title bar.

I didn't found any option to not show this title bar within the browser
widget. Do I have to live with it or is there an option or a trick I haven't
found yet?

Thanks

Tiemo