[#5] Implement Splash screen

lib/main.dart

@@ -4,32 +4,25 @@ import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:survey_flutter/gen/assets.gen.dart';
 import 'package:go_router/go_router.dart';
 import 'package:package_info_plus/package_info_plus.dart';
+import 'package:survey_flutter/screens/splash/splash.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await FlutterConfig.loadEnvVariables();
   runApp(MyApp());
 }
 
-const routePathRootScreen = '/';
-const routePathSecondScreen = 'second';
+const routePathSplashScreen = '/';
 
 class MyApp extends StatelessWidget {
   MyApp({Key? key}) : super(key: key);
 
   final GoRouter _router = GoRouter(
     routes: <GoRoute>[
       GoRoute(
-        path: routePathRootScreen,
+        path: routePathSplashScreen,
         builder: (BuildContext context, GoRouterState state) =>
-            const HomeScreen(),
-        routes: [
-          GoRoute(
-            path: routePathSecondScreen,
-            builder: (BuildContext context, GoRouterState state) =>
-                const SecondScreen(),
-          ),
-        ],
+            const SplashScreen()
       ),
     ],
   );
@@ -83,11 +76,7 @@ class HomeScreen extends StatelessWidget {
               FlutterConfig.get('SECRET'),
               style: const TextStyle(color: Colors.black, fontSize: 24),
             ),
-            const SizedBox(height: 24),
-            ElevatedButton(
-              onPressed: () => context.go('/$routePathSecondScreen'),
-              child: const Text("Navigate to Second Screen"),
-            ),
+            const SizedBox(height: 24)
           ],
         ),
       ),

lib/screens/splash/splash.dart

@@ -0,0 +1,64 @@
+import 'package:flutter/material.dart';
+import 'package:survey_flutter/gen/assets.gen.dart';
+class SplashScreen extends StatefulWidget {
+  const SplashScreen({Key? key}) : super(key: key);
+
+  @override
+  State<StatefulWidget> createState() => SplashScreenState();
+}
+
+class SplashScreenState extends State<SplashScreen> {
+  bool _isLogoVisible = false;
+  bool _shouldStartAnimate = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _delayedLogoVisibility();
+  }
+
+  void _delayedLogoVisibility() async {
+    await Future.delayed(const Duration(seconds: 1));
+    setState(() {
+      _isLogoVisible = true;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: LayoutBuilder(builder: (context, constraints) {
+        return Stack(
+          alignment: AlignmentDirectional.center,
+          fit: StackFit.expand,
+          children: [
+            Image.asset(
+              Assets.images.splashBackground.path,
+              fit: BoxFit.cover,
+            ),
+            _buildAnimatedLogo(constraints),
+          ],
+        );
+      }),
+    );
+  }
+
+  Widget _buildAnimatedLogo(BoxConstraints constraints) {
+    return AnimatedPositioned(
+      duration: const Duration(seconds: 1),
+      top: _shouldStartAnimate ? 153.0 : constraints.maxHeight / 2.0,
+      child: AnimatedOpacity(
+        opacity: _isLogoVisible ? 1.0 : 0.0,
+        duration: const Duration(milliseconds: 500),
+        child: Image.asset(
+          Assets.images.splashLogoWhite.path,
+        ),
+        onEnd: () {
+          setState(() {
+            _shouldStartAnimate = true;
+          });
+        },
+      ),
+    );
+  }
+}