Scrollbars are controlled by GTK theme not Geany. Options are:
1. change the GTK theme on your system to one with wider scrollbars 2. edit the GTK tweak CSS ~/.config/gtk-3.0/gtk.css as below (don't do this unless you want it to apply to all apps) 3. edit geany.css (`Menu->Tools->Configuration Files->geany.css`) as below
Add below to CSS (changing the numbers to suit your screen and eyes, those are probably too big but make it visible it worked) and restart Geany.
``` scrollbar slider { /* Size of the slider */ min-width: 20px; min-height: 20px; border-radius: 22px;
/* Padding around the slider */ border: 5px solid transparent; } ```