I've recently updated a few programs to gtk3 (deadbeef gtk3 plugin, pcmanfm-gtk3, l3afpad) and there's one thing that's really been bugging me:
Why is the Statusbar thrice the height of the gtk2 version?
It's clearly not because there's more information or a bigger font - the text is the same for both versions, it's just a 10 px margin for the statusbar in gtk3. So I thought "hey, gtk3 has some nice CSS, maybe I can tweak that with gtk.css oder settings.ini" - turns out that nah, not really. Any stuff in gtk.css like
GtkStatusbar { margin:0px; margin-top:0px; margin-bottom:0px; }
doesn't do anything, sadly.
So I tried playing around with GtkInspector in pcmanfm. When I select the whole Statusbar element (you have to select the whitespace between the left and the right labels, only 10 px wide) and I check the properties, I see theres a 10 px value for all margins defined for GtkWidget (except for bottom and top, those are 6). Now if I doubleclick that value and set "all margins" to 0 it immediately gives me a gtk2 statusbar - rejoice!
So I know it is possible, but I just haven't found a way to get that into gtk.css. I got desperate enough to try:
GtkWidget { margin:0px; margin-top:0px; margin-bottom:0px; }
but I didn't really expect it to work - so of course it didn't.
I've also tried searching for solutions online, but I've only ended up with a few very specific tips to downgrade eclipse from gtk3 to gtk2 in order to save screen space or this patch to engrampa that removes those margins.
Hell, it could be there's some GUI-Tool for GNOME that does this in like 5 seconds, and I've been searching for the wrong stuff all along.
dpkg -l libgtk-3-0
*.scss
(Arc or Numix) or have binary "blobs" (Adwaita).