Custom CSS for play button

data/gtk/style-dark.css

@@ -1,2 +1,7 @@
 @define-color accent_color @purple_1;
 @define-color accent_bg_color @purple_4;
+
+#overview_launch {
+    color: @dark_5;
+    background-color: @light_1;
+}

data/gtk/style.css

@@ -1,2 +1,8 @@
 @define-color accent_color @purple_5;
 @define-color accent_bg_color @purple_3;
+
+#overview_launch {
+    color: @light_1;
+    background-color: @dark_5;
+    opacity: 0.8;
+}

data/gtk/window.blp

@@ -146,13 +146,13 @@ template CartridgesWindow : Adw.ApplicationWindow {
                   valign: center;
 
                   Button overview_launch {
+                    name: "overview_launch";
                     action-name: "app.launch_game";
                     label: _("Play");
                     halign: start;
                     margin-top: 24;
 
                     styles [
-                      "suggested-action",
                       "pill",
                     ]
                   }