slider works.. kinda

.config/gtk-3.0/gtk-widgets.css

@@ -172,6 +172,21 @@ button {
     text-shadow: none;
 }
 
+scale {
+    background: @bg_color;
+}
+
+scale trough *,
+scale:hover trough * {
+    background: @acc1_color;
+}
+
+scale trough,
+scale:hover trough {
+    background: mix(@fg_color, @bg_color, 0.5);
+}
+
+
 button:hover label,
 button:focus label,
 switch:hover slider,