GNOME theme: GTK colors follow the light/dark style; adw-gtk3

lib/gnome-theme.sh

@@ -117,7 +117,8 @@ gnometheme_enable() {
     info "Applying the SteamOS look to GNOME..."
     gset gnometheme org.gnome.desktop.interface color-scheme "'prefer-dark'"
     gset gnometheme org.gnome.desktop.interface accent-color "'blue'" || true
-    gset gnometheme org.gnome.desktop.interface gtk-theme "'Vapor'" || true
+    # adw-gtk3 follows the light/dark style of Settings > Appearance (CachyOS's adw-gtk3-dark would pin it dark).
+    [[ -d /usr/share/themes/adw-gtk3 ]] && gset gnometheme org.gnome.desktop.interface gtk-theme "'adw-gtk3'"
     # Windows with minimize and maximize buttons, like Ubuntu (GNOME shows only close by default).
     gset gnometheme org.gnome.desktop.wm.preferences button-layout "'appmenu:minimize,maximize,close'" || true
     if [[ -f "$GNOME_THEME_WALLPAPER" ]]; then

patches/steamify-gnome-gtk4.css

@@ -1,4 +1,9 @@
-/* Steamify Vapor: libadwaita/GTK4 colors, from Vapor's palette (cachyos-vapor, Vapor.colors). */
+/* Steamify Vapor: libadwaita/GTK4 colors. In the dark style: Vapor's palette (cachyos-vapor, Vapor.colors);
+ * in the light style (Settings > Appearance): libadwaita's own light colors, with Vapor's blue accent. */
+@define-color accent_bg_color #2a8fd0;
+@define-color accent_fg_color #ffffff;
+@define-color accent_color #1b6ea7;
+@media (prefers-color-scheme: dark) {
   @define-color accent_bg_color #569fcc;
   @define-color accent_fg_color #1f1f26;
   @define-color accent_color #3daee9;
@@ -12,3 +17,4 @@
   @define-color popover_bg_color #2a2e32;
   @define-color sidebar_bg_color #1f2328;
   @define-color dialog_bg_color #2a2e32;
+}