criada alguns widgets padrões e ajustada a tela de login

lib/main.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:rkm/screens/login_screen.dart';
+import 'package:rkm/utils/color_palette.dart';
 import 'package:rkm/utils/routes.dart';
 void main() {
   runApp(const MyApp());
@@ -10,8 +10,13 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
+      theme: ThemeData(
+        primaryColor: ColorPalette.primary,
+        appBarTheme: AppBarTheme(
+          color: ColorPalette.primary
+        )
+      ),
       debugShowCheckedModeBanner: false,
-      home: LoginScreen(),
       initialRoute: '/login',
       routes: routes,
     );