diff --git a/src/gtk3/applications/_firefox.scss b/src/gtk3/applications/_firefox.scss
new file mode 100644
--- /dev/null
+++ b/src/gtk3/applications/_firefox.scss
@@ -0,0 +1,8 @@
+#MozillaGtkWidget {
+    scrollbar {
+        margin: 0px;
+        slider {
+            border: 5px solid transparent;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/gtk3/gtk.scss b/src/gtk3/gtk.scss
--- a/src/gtk3/gtk.scss
+++ b/src/gtk3/gtk.scss
@@ -34,4 +34,5 @@
 @import "widgets/treeview";
 @import "widgets/window_decorations";
 
-@import "applications/chromium";
\ No newline at end of file
+@import "applications/chromium";
+@import "applications/firefox";
\ No newline at end of file