diff --git a/data/cartridges.gresource.xml b/data/cartridges.gresource.xml
index 89d5a9b..bdbd1b0 100644
--- a/data/cartridges.gresource.xml
+++ b/data/cartridges.gresource.xml
@@ -5,6 +5,8 @@
     <file preprocess="xml-stripblanks">gtk/help-overlay.ui</file>
     <file preprocess="xml-stripblanks">gtk/game.ui</file>
     <file preprocess="xml-stripblanks">gtk/preferences.ui</file>
+    <file alias="style.css">gtk/style.css</file>
+    <file alias="style-dark.css">gtk/style-dark.css</file>
     <file>library_placeholder.svg</file>
   </gresource>
 </gresources>
diff --git a/data/gtk/style-dark.css b/data/gtk/style-dark.css
new file mode 100644
index 0000000..ffb47c5
--- /dev/null
+++ b/data/gtk/style-dark.css
@@ -0,0 +1,2 @@
+@define-color accent_color @purple_1;
+@define-color accent_bg_color @purple_4;
diff --git a/data/gtk/style.css b/data/gtk/style.css
new file mode 100644
index 0000000..25f2373
--- /dev/null
+++ b/data/gtk/style.css
@@ -0,0 +1,2 @@
+@define-color accent_color @purple_5;
+@define-color accent_bg_color @purple_3;