In a Vaadin 14.4.2 application with Lumo theme there are the top pixels cut off in Firefox browser running in Ubuntu (20.10), GNOME 3.38.1:
This happens in my applications and also in the Vaadin demo Lumo theme editor: https://demo.vaadin.com/lumo-editor/
I guess that this behavior is because of the Lumo font family variable:
--lumo-font-family: -apple-system, BlinkMacSystemFont, "Roboto", "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"; and because something (I don't know what it is) limits the size of the label element.
In my Ubuntu system there is something for "sans-serif" available, but none of the other fonts.
Solution approach: When I extend the list of font-families by e.g. "DejaVu Sans" (which is available at my Ubuntu system) the label looks fine. So this could be a solution.
But maybe there's another system configuration where this font is also not available and the Firefox also cuts off the top pixels. Is there a more general solution?