fix navbar matching when using global back button

lib/components/login/login.dart

@@ -113,18 +113,29 @@ class _LoginPanelContentState extends State<LoginPanelContent> {
   final _usernameController = TextEditingController();
   final _passwordController = TextEditingController();
 
+  bool _loggingIn = false;
+
   void login() async {
     final username = _usernameController.text;
     final password = _passwordController.text;
 
     final auth = context.read<AuthService>();
 
+    setState(() {
+      _loggingIn = true;
+    });
     try {
       auth.login(username, password);
       print('Login successful');
+      setState(() {
+        _loggingIn = false;
+      });
     } catch (e) {
       // Handle error
       print('Login failed: $e');
+      setState(() {
+        _loggingIn = false;
+      });
       ScaffoldMessenger.of(
         context,
       ).showSnackBar(SnackBar(content: Text('Login failed')));
@@ -133,6 +144,15 @@ class _LoginPanelContentState extends State<LoginPanelContent> {
 
   @override
   Widget build(BuildContext context) {
+    Widget loginButtonContent = Text("Login");
+    if (_loggingIn) {
+      loginButtonContent = Padding(
+        padding: const EdgeInsets.all(8.0),
+        child: CircularProgressIndicator(),
+      );
+    } else {
+      loginButtonContent = Text("Login");
+    }
     return Column(
       mainAxisAlignment: MainAxisAlignment.center,
       mainAxisSize: MainAxisSize.min,
@@ -164,7 +184,7 @@ class _LoginPanelContentState extends State<LoginPanelContent> {
           mainAxisAlignment: MainAxisAlignment.center,
           spacing: 10,
           children: [
-            FilledButton(onPressed: login, child: Text("Login")),
+            FilledButton(onPressed: login, child: loginButtonContent),
             ElevatedButton(
               onPressed: widget.registerCb,
               child: Text("Register"),