Chrome sometimes seems to have problems when using a blur
backdrop-filter in combination with opacity. On Linux, this often
results in the blur being completely ignored. This also seems to apply
to other systems, though. See the following issue for more details:
https://bugs.chromium.org/p/chromium/issues/detail?id=1129838
Making the background opaque using rgba seems to fix the problem.
backend: pass plugin button generated code through domdocument to ensure
its correctness; set data-plugin-name attribute on children to make
them sortable via css
Michael Kuhn
Andrew Dolgov