Use root properties instead of the * selector

This works around https://github.com/vizia/vizia/issues/131, which was
the reason why the vizia update was reverted.

nih_plug_vizia/assets/theme.css

@@ -1,11 +1,5 @@
 /* Overrides for default VIZIA widgets */
 
-* {
-  color: #0a0a0a;
-  /* VIZIA uses points instead of pixels, this is 20px */
-  font-size: 15;
-}
-
 scrollview > vstack {
   /* Normally the scroll bar overlaps with the content, so we'll add a little offset to prevent that */
   child-right: 15px;

nih_plug_vizia/src/lib.rs

@@ -167,6 +167,9 @@ impl Editor for ViziaEditor {
 
                 // TOOD: `:root { background-color: #fafafa; }` in a stylesheet doesn't work
                 Entity::root().set_background_color(cx, Color::rgb(250, 250, 250));
+                Entity::root().set_color(cx, Color::rgb(10, 10, 10));
+                // VIZIA uses points instead of pixels, this is 20px
+                Entity::root().set_font_size(cx, 15.0);
                 cx.add_theme(include_str!("../assets/theme.css"));
 
                 // There doesn't seem to be any way to bundle styles with a widget, so we'll always