diff --git a/modules/firefox.nix b/modules/firefox/default.nix
similarity index 95%
rename from modules/firefox.nix
rename to modules/firefox/default.nix
index 26d4a23..b87c9be 100644
--- a/modules/firefox.nix
+++ b/modules/firefox/default.nix
@@ -52,6 +52,8 @@ with lib; {
     # TODO: Consider other themes
     # https://github.com/soulhotel/FF-ULTIMA
 
+    # BUG: Tab groups not yet supported
+    # https://github.com/rafaelmardojai/firefox-gnome-theme/issues/901
     # Import CSS theme with solarized overrides
     # https://github.com/rafaelmardojai/firefox-gnome-theme
     # https://github.com/rafaelmardojai/firefox-gnome-theme/blob/master/theme/colors/dark.css
@@ -61,37 +63,7 @@ with lib; {
 
     userChrome = mkIf theme ''
       @import "${inputs.firefox-gnome-theme}/userChrome.css";
-
-      :root {
-        --gnome-accent: #d33682;
-        --gnome-window-background: #002b36;
-        --gnome-window-color: #93a1a1;
-        --gnome-view-background: #073642;
-        --gnome-sidebar-background: #002b36;
-        --gnome-secondary-sidebar-background: #002b36;
-        --gnome-menu-background: #073642;
-        --gnome-headerbar-background: #002b36;
-        --gnome-toolbar-icon-fill: #93a1a1;
-        --gnome-tabbar-tab-hover-background: #073642;
-        --gnome-tabbar-tab-active-background: #073642;
-        --gnome-tabbar-tab-active-hover-background: #073642;
-      }
-
-      :root:-moz-window-inactive {
-        --gnome-inactive-entry-color: #586e75;
-        --gnome-tabbar-tab-hover-background: #073642;
-        --gnome-tabbar-tab-active-background: #073642;
-      }
-
-      /* Center bookmarks */
-      #PlacesToolbarItems {
-        justify-content: center;
-      }
-
-      /* Disable bookmark folder icons */
-      .bookmark-item[container] > .toolbarbutton-icon {
-        display: none;
-      }
+      ${builtins.readFile ./userChrome.css}
     '';
 
     containersForce = true;
diff --git a/modules/firefox/userChrome.css b/modules/firefox/userChrome.css
new file mode 100644
index 0000000..5cf491b
--- /dev/null
+++ b/modules/firefox/userChrome.css
@@ -0,0 +1,34 @@
+/***
+https://github.com/rafaelmardojai/firefox-gnome-theme
+***/
+
+:root {
+  --gnome-accent: #d33682;
+  --gnome-window-background: #002b36;
+  --gnome-window-color: #93a1a1;
+  --gnome-view-background: #073642;
+  --gnome-sidebar-background: #002b36;
+  --gnome-secondary-sidebar-background: #002b36;
+  --gnome-menu-background: #073642;
+  --gnome-headerbar-background: #002b36;
+  --gnome-toolbar-icon-fill: #93a1a1;
+  --gnome-tabbar-tab-hover-background: #073642;
+  --gnome-tabbar-tab-active-background: #073642;
+  --gnome-tabbar-tab-active-hover-background: #073642;
+}
+
+:root:-moz-window-inactive {
+  --gnome-inactive-entry-color: #586e75;
+  --gnome-tabbar-tab-hover-background: #073642;
+  --gnome-tabbar-tab-active-background: #073642;
+}
+
+/* Center bookmarks */
+#PlacesToolbarItems {
+  justify-content: center;
+}
+
+/* Disable bookmark folder icons */
+.bookmark-item[container] > .toolbarbutton-icon {
+  display: none;
+}
diff --git a/options/custom/programs/firefox/firefox.nix b/options/custom/programs/firefox/firefox.nix
index 0635f64..54a6db0 100644
--- a/options/custom/programs/firefox/firefox.nix
+++ b/options/custom/programs/firefox/firefox.nix
@@ -17,7 +17,7 @@ in {
       {
         # https://www.mozilla.org/en-US/firefox/developer
         programs.firefox = mkMerge [
-          (import "${inputs.self}/modules/firefox.nix" {inherit config inputs lib pkgs;})
+          (import "${inputs.self}/modules/firefox/default.nix" {inherit config inputs lib pkgs;})
 
           {
             enable = true;
diff --git a/options/custom/programs/firefox/librewolf.nix b/options/custom/programs/firefox/librewolf.nix
index 44033f7..7ed5235 100644
--- a/options/custom/programs/firefox/librewolf.nix
+++ b/options/custom/programs/firefox/librewolf.nix
@@ -18,7 +18,7 @@ in {
         # https://librewolf.net/
         # https://codeberg.org/librewolf
         programs.librewolf = mkMerge [
-          (import "${inputs.self}/modules/firefox.nix" {inherit config inputs lib pkgs;})
+          (import "${inputs.self}/modules/firefox/default.nix" {inherit config inputs lib pkgs;})
 
           {
             enable = true;
diff --git a/options/custom/programs/firefox/zen-browser.nix b/options/custom/programs/firefox/zen-browser.nix
index edfd35f..46e7544 100644
--- a/options/custom/programs/firefox/zen-browser.nix
+++ b/options/custom/programs/firefox/zen-browser.nix
@@ -18,7 +18,7 @@ in {
         # https://zen-browser.app/
         # https://github.com/youwen5/zen-browser-flake
         programs.zen-browser = mkMerge [
-          (import "${inputs.self}/modules/firefox.nix" {
+          (import "${inputs.self}/modules/firefox/default.nix" {
             inherit config inputs lib pkgs;
 
             # TODO: Revisit Zen themes