diff --git a/i3/config b/i3/config
index bdaca6e..127c3eb 100644
--- a/i3/config
+++ b/i3/config
@@ -34,6 +34,9 @@ exec --no-startup-id xss-lock --transfer-sleep-lock -- i3lock -f --nofork
 # and nm-applet is a desktop environment-independent system tray GUI for it.
 exec --no-startup-id nm-applet
 
+# Start picom compositor for transparency effects
+exec --no-startup-id picom -b
+
 # Use pactl to adjust volume in PulseAudio.
 set $refresh_i3status killall -SIGUSR1 i3status
 bindsym XF86AudioRaiseVolume exec --no-startup-id pactl set-sink-volume @DEFAULT_SINK@ +10% && $refresh_i3status
@@ -152,6 +155,12 @@ set $ws8 "8"
 set $ws9 "9"
 set $ws10 "10"
 
+# Mouse side button bindings for MX Master 3S
+# Button 8 (Back) - Focus next window
+bindsym --whole-window button8 focus next
+# Button 9 (Forward) - Focus previous window
+bindsym --whole-window button9 focus prev
+
 # switch to workspace
 bindsym $mod+1 workspace number $ws1
 bindsym $mod+2 workspace number $ws2
diff --git a/picom/picom.conf b/picom/picom.conf
new file mode 100644
index 0000000..f6f5e43
--- /dev/null
+++ b/picom/picom.conf
@@ -0,0 +1,53 @@
+# Backend
+backend = "glx";
+
+# GLX backend
+glx-no-stencil = true;
+glx-copy-from-front = false;
+
+# Opacity
+active-opacity = 1;
+inactive-opacity = 1;
+frame-opacity = 1;
+inactive-opacity-override = false;
+
+# Blur
+blur-background = false;
+
+# Fading
+fading = true;
+fade-delta = 4;
+fade-in-step = 0.03;
+fade-out-step = 0.03;
+
+# Other
+mark-wmwin-focused = true;
+mark-ovredir-focused = true;
+detect-rounded-corners = true;
+detect-client-opacity = true;
+refresh-rate = 0;
+vsync = true;
+dbe = false;
+unredir-if-possible = false;
+focus-exclude = [ ];
+detect-transient = true;
+detect-client-leader = true;
+
+# Window type settings
+wintypes:
+{
+    tooltip =
+    {
+        fade = true;
+        shadow = false;
+        opacity = 0.85;
+        focus = true;
+    };
+    fullscreen =
+    {
+        fade = true;
+        shadow = false;
+        opacity = 1;
+        focus = true;
+    };
+};
\ No newline at end of file