diff --git a/Gtk4/gtk160_wayland_test/res/style.css b/Gtk4/gtk160_wayland_test/res/style.css
index 1bdf263..a5b29f6 100644
--- a/Gtk4/gtk160_wayland_test/res/style.css
+++ b/Gtk4/gtk160_wayland_test/res/style.css
@@ -1,10 +1,15 @@
 
 /* A slim headerbar style for widgets */
-headerbar{
+.titlebar{
 	min-height:10px;
 	margin:0px;
 }
 
+label{
+	margin: 0px;
+	min-height: 8px;
+}
+
 .ctrl_btn{
 	min-height: 8px;
 	min-width: 8px;
diff --git a/Gtk4/gtk160_wayland_test/src/main.cpp b/Gtk4/gtk160_wayland_test/src/main.cpp
index 3dce38e..2fc8bad 100644
--- a/Gtk4/gtk160_wayland_test/src/main.cpp
+++ b/Gtk4/gtk160_wayland_test/src/main.cpp
@@ -13,19 +13,23 @@ static void gtkmain(GtkApplication *app, gpointer user_data)
     // Create widgets
     window = gtk_application_window_new(app);
     header = gtk_header_bar_new();
+
+    const char *title_classes[] = {"titlebar", ""};
+    gtk_widget_set_css_classes(header, title_classes);
     gtk_window_set_titlebar(GTK_WINDOW(window), header);
 
     // Initalize headerbar
     gtk_header_bar_set_show_title_buttons(GTK_HEADER_BAR(header), FALSE);
+    const char *btn_classes[] = {"ctrl_btn",""};
 
     // Add a close button
     btn_close = gtk_button_new_with_label("\u00d7");
-    gtk_widget_add_css_class(btn_close, "ctrl_btn");
+    gtk_widget_set_css_classes(btn_close, btn_classes);
     gtk_header_bar_pack_start(GTK_HEADER_BAR(header), btn_close);
 
     // Add a minimize button
     btn_mini = gtk_button_new_with_label("-");
-    gtk_widget_add_css_class(btn_mini, "ctrl_btn");
+    gtk_widget_set_css_classes(btn_mini, btn_classes);
     gtk_header_bar_pack_start(GTK_HEADER_BAR(header), btn_mini);
 
     // Add style for headerbar