fix navigation bar appearance

@@ -39,6 +39,22 @@ extension UIViewController {
         let leftBarButtonItem: UIBarButtonItem = UIBarButtonItem(customView: backButton)
         self.navigationItem.setLeftBarButton(leftBarButtonItem, animated: false)
         self.navigationItem.title = ""
+
+        // Add backgroundColor
+        let navigationBarAppearance = UINavigationBarAppearance()
+        navigationBarAppearance.configureWithDefaultBackground()
+        navigationBarAppearance.backgroundColor = .white
+
+        navigationItem.standardAppearance = navigationBarAppearance
+        navigationItem.compactAppearance = navigationBarAppearance
+        navigationItem.scrollEdgeAppearance = navigationBarAppearance
+        
+        // Add shadow
+        self.navigationController?.navigationBar.layer.masksToBounds = false
+        self.navigationController?.navigationBar.layer.shadowColor = UIColor.lightGray.cgColor
+        self.navigationController?.navigationBar.layer.shadowOpacity = 0.8
+        self.navigationController?.navigationBar.layer.shadowOffset = CGSize(width: 0, height: 2.0)
+        self.navigationController?.navigationBar.layer.shadowRadius = 2
     }