That is not how you comment in CSS
diff --git a/src/apps/personal/waybar.nix b/src/apps/personal/waybar.nix
index a2d800c..4e20cae 100644
--- a/src/apps/personal/waybar.nix
+++ b/src/apps/personal/waybar.nix
@@ -73,7 +73,6 @@
 
             window#waybar #workspaces button, window#waybar #workspaces button {
                 border: 0;
-                # background: alpha(@theme_base_color, 0.3);
             }
 
             window#waybar #workspaces button.focused {