diff --git a/src/tabbar/_box_shadow.scss b/src/tabbar/_box_shadow.scss
new file mode 100644
index 0000000..4b433a1
--- /dev/null
+++ b/src/tabbar/_box_shadow.scss
@@ -0,0 +1,21 @@
+#TabsToolbar[brighttext]
+  #tabbrowser-tabs:not([noshadowfortests])
+  .tabbrowser-tab[visuallyselected="true"]:not(:focus)
+  > .tab-stack
+  > .tab-background:-moz-lwtheme {
+  /* Origina: 0 0 1px var(--tab-line-color, rgba(128,128,142,0.9))
+       Bright: 0 0 1px var(--tab-line-color, rgba(128,128,142,0.9)), 0 0 4px rgba(128,128,142,0.5) */
+  box-shadow: 0 0 1px var(--toolbar-color) !important;
+}
+#TabsToolbar[brighttext]
+  #tabbrowser-tabs:not([noshadowfortests])
+  .tabbrowser-tab[multiselected]:not([visuallyselected])
+  > .tab-stack
+  > .tab-background:-moz-lwtheme {
+  box-shadow: 0 0 1px color-mix(in srgb, var(--toolbar-color) 80%, transparent) !important;
+}
+
+/* Pinned Tab - tabbrowser-arrowscrollbox overflowing */
+#tabbrowser-tabs[positionpinnedtabs] > #tabbrowser-arrowscrollbox > .tabbrowser-tab[pinned] {
+  z-index: 0 !important;
+}
diff --git a/src/userChrome.scss b/src/userChrome.scss
index baafa41..e850907 100644
--- a/src/userChrome.scss
+++ b/src/userChrome.scss
@@ -44,27 +44,7 @@
 @import "tabbar/color_like_toolbar";
 
 /** Selected Tab - Box Shadow *************************************************/
-#TabsToolbar[brighttext]
-  #tabbrowser-tabs:not([noshadowfortests])
-  .tabbrowser-tab[visuallyselected="true"]:not(:focus)
-  > .tab-stack
-  > .tab-background:-moz-lwtheme {
-  /* Origina: 0 0 1px var(--tab-line-color, rgba(128,128,142,0.9))
-       Bright: 0 0 1px var(--tab-line-color, rgba(128,128,142,0.9)), 0 0 4px rgba(128,128,142,0.5) */
-  box-shadow: 0 0 1px var(--toolbar-color) !important;
-}
-#TabsToolbar[brighttext]
-  #tabbrowser-tabs:not([noshadowfortests])
-  .tabbrowser-tab[multiselected]:not([visuallyselected])
-  > .tab-stack
-  > .tab-background:-moz-lwtheme {
-  box-shadow: 0 0 1px color-mix(in srgb, var(--toolbar-color) 80%, transparent) !important;
-}
-
-/* Pinned Tab - tabbrowser-arrowscrollbox overflowing */
-#tabbrowser-tabs[positionpinnedtabs] > #tabbrowser-arrowscrollbox > .tabbrowser-tab[pinned] {
-  z-index: 0 !important;
-}
+@import "tabbar/box_shadow";
 
 /** Selected Tab - Bottom Rounded Corner **************************************/
 #tabbrowser-tabs {