diff --git a/_chrome__firefox/userChrome.css b/_chrome__firefox/userChrome.css
new file mode 100644
index 0000000..32d2aec
--- /dev/null
+++ b/_chrome__firefox/userChrome.css
@@ -0,0 +1,3 @@
+#sidebar-box {
+  background-color: #333 !important;
+}
diff --git a/_chrome__firefox/userContent.css b/_chrome__firefox/userContent.css
new file mode 100644
index 0000000..fb361d0
--- /dev/null
+++ b/_chrome__firefox/userContent.css
@@ -0,0 +1,5 @@
+@-moz-document url("about:newtab") {
+  body {
+    background-color: #333 !important;
+  }
+}