After updating Gnome to 3.18 on my Debian box, all the icons became unacceptably large compared to what I had before. Is there a config file I need to edit to shrink the icon size? I tried following this guide, editing all 96px to 48px and 136px to 68px in /usr/share/gnome-shell/theme/gnome-classic.css. After a reboot, the icons are still the same.
Gnome 3.18 icon size
gnome3;icons