Fixing track volume slider width in Firefox
Fixing track volume slider width in Firefox

Previously, the sliders expanded out of the track header box. I'm
guessing it previously worked correctly in older versions of Firefox,
(I tested in v65.0.1), but I don't have an older version around for
testing.

Not sure why this CSS works, but at least it fixes the problem...

jstrait/jssynth,jstrait/jssynth