Hint if you&#x27;re looking for other css selectors to make additional customizations: to inspect any GTK3 app under GNOME ≥ 3.14, just set the gsetting mentioned at [1], and Ctrl+Shift+I to get a Chrome&#x2F;Firefox devtools-like inspector :)<p>[1] <a href="https:&#x2F;&#x2F;wiki.gnome.org&#x2F;Projects&#x2F;GTK%2B&#x2F;Inspector" rel="nofollow">https:&#x2F;&#x2F;wiki.gnome.org&#x2F;Projects&#x2F;GTK%2B&#x2F;Inspector</a>