Use Super (AKA Windows) key mod

dotfiles/i3/config

@@ -9,7 +9,7 @@
 #
 # Please see http://i3wm.org/docs/userguide.html for a complete reference!
 
-set $mod Mod1
+set $mod Mod4
 
 # Font for window titles. Will also be used by the bar unless a different font
 # is used in the bar {} block below.