Ubuntu – How to disable the drop shadow effect at the edge of windows in Gnome Shell

13.04gnomeubuntu-gnomewindow-decoration

Here is:

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I try to find in gnome-tweak-tool, but I have no luck. I'm using Gnome Shell v3.8.3 on Ubuntu Gnome 13.04.

(Not tested)

Edit the theme manually by adding the following to ~/.config/gtk-3.0/gtk.css:

.window-frame {box-shadow: none;}