move scale factors to constraints

scenes/ui/MainMenu.gd

@@ -87,7 +87,7 @@ func _update_visual_selection() -> void:
 	for i in range(menu_buttons.size()):
 		var button: Button = menu_buttons[i]
 		if i == current_menu_index:
-			button.scale = original_button_scales[i] * 1.1
+			button.scale = original_button_scales[i] * UIConstants.BUTTON_HOVER_SCALE
 			button.modulate = Color(1.2, 1.2, 1.0)
 		else:
 			button.scale = original_button_scales[i]

scenes/ui/SettingsMenu.gd

@@ -212,7 +212,7 @@ func _update_visual_selection() -> void:
 			if control == language_stepper:
 				language_stepper.set_highlighted(true)
 			else:
-				control.scale = original_control_scales[i] * 1.05
+				control.scale = original_control_scales[i] * UIConstants.UI_CONTROL_HIGHLIGHT_SCALE
 				control.modulate = Color(1.1, 1.1, 0.9)
 		else:
 			# Reset highlighting

scenes/ui/components/ValueStepper.gd

@@ -175,7 +175,7 @@ func set_current_value(value: String) -> void:
 func set_highlighted(highlighted: bool) -> void:
 	is_highlighted = highlighted
 	if highlighted:
-		scale = original_scale * 1.05
+		scale = original_scale * UIConstants.UI_CONTROL_HIGHLIGHT_SCALE
 		modulate = Color(1.1, 1.1, 0.9)
 	else:
 		scale = original_scale