
Since commit 447bf55e45
we turn the top bar translucent when
free-floating. While this looks fancy and reduces the appearance
of cutting into the available screen space, it has also had a
negative effect on legibility.
Nobody stepped up to address those issues in two years, so revert
back to the fully opaque top bar.
https://gitlab.gnome.org/GNOME/gnome-shell/issues/408