diff --git a/lib/main.dart b/lib/main.dart
index fa18709..604e9d2 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -1,6 +1,9 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:hashcode/custom/custom_colors.dart';
 import 'package:hashcode/screens/home.dart';
+import 'package:hashcode/theme.dart';
+import 'package:provider/provider.dart';
 
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
@@ -8,11 +11,33 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
+  
   @override
   Widget build(BuildContext context) {
+    SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.dark.copyWith(
+      statusBarColor: Colors.black, //set status bar color
+    ));
+    return ChangeNotifierProvider<ThemeChanger>(
+      builder: (context)=> ThemeChanger(ThemeData.dark()),
+      child: HashCodeApp()
+    );
+  }
+}
+
+
+class HashCodeApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    final theme = Provider.of<ThemeChanger>(context);
     return MaterialApp(
-      theme: ThemeData(accentColor: customDarkBlack),
+        debugShowCheckedModeBanner: true,
+        title: 'HashCode App',
       home: Home(),
+      theme: theme.getTheme(),
     );
   }
 }
+
+
+
+
diff --git a/lib/screens/about_topic.dart b/lib/screens/about_topic.dart
index f9eca9e..5a19e41 100644
--- a/lib/screens/about_topic.dart
+++ b/lib/screens/about_topic.dart
@@ -38,7 +38,6 @@ class _AboutTopicState extends State<AboutTopic> {
   Widget build(BuildContext context) {
     final appBar = AppBar(
       elevation: 1.0,
-      backgroundColor: customDarkBlack,
       title: Text('About'),
       centerTitle: true,
       leading: IconButton(
@@ -101,7 +100,6 @@ class _AboutTopicState extends State<AboutTopic> {
     );
 
     return Scaffold(
-      backgroundColor: customDarkBlack,
       appBar: appBar,
       body: body,
     );
diff --git a/lib/screens/code.dart b/lib/screens/code.dart
index d04b229..e01d918 100644
--- a/lib/screens/code.dart
+++ b/lib/screens/code.dart
@@ -26,7 +26,6 @@ class _CodeState extends State<Code> {
   Widget build(BuildContext context) {
     final appBar = AppBar(
       elevation: 1.0,
-      backgroundColor: customDarkBlack,
       title: Text('About'),
       centerTitle: true,
       leading: IconButton(
diff --git a/lib/screens/home.dart b/lib/screens/home.dart
index 2a396e2..fc4002c 100644
--- a/lib/screens/home.dart
+++ b/lib/screens/home.dart
@@ -4,20 +4,31 @@ import 'package:hashcode/custom/custom_colors.dart';
 import 'package:hashcode/custom/custom_gifs.dart';
 import 'package:hashcode/custom/page_transitions/slide_left_route.dart';
 import 'package:hashcode/screens/lessons.dart';
+import 'package:hashcode/theme.dart';
+import 'package:provider/provider.dart';
 
 class Home extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
+     ThemeChanger _themeChanger = Provider.of<ThemeChanger>(context);
     final body = CustomScrollView(
       physics: BouncingScrollPhysics(),
       slivers: [
         SliverAppBar(
           floating: true,
           pinned: false,
-          backgroundColor: customDarkBlack,
           elevation: 1.0,
           title: Text('Dashboard'),
           actions: [
+               Switch(
+                        value: _themeChanger.isLightTheme,
+                        onChanged: (lightDark) {
+                          if (lightDark)
+                            _themeChanger.setTheme(ThemeData(primaryColor: Colors.white));
+                          else
+                            _themeChanger.setTheme(ThemeData.dark());
+                        }),
+
             GestureDetector(
               onTap: () {
                 Navigator.push(context, SlideLeftRoute(page: Lessons()));
@@ -68,7 +79,7 @@ class Home extends StatelessWidget {
     );
 
     return Scaffold(
-      backgroundColor: customDarkBlack,
+     
       body: body,
     );
   }
diff --git a/lib/screens/lessons.dart b/lib/screens/lessons.dart
index 80593ed..72b92a9 100644
--- a/lib/screens/lessons.dart
+++ b/lib/screens/lessons.dart
@@ -21,7 +21,6 @@ class Lessons extends StatelessWidget {
           centerTitle: true,
           title: Text('Lessons'),
           elevation: 1.0,
-          backgroundColor: customDarkBlack,
           leading: IconButton(
             icon: Icon(Icons.arrow_back),
             onPressed: () {
@@ -37,7 +36,7 @@ class Lessons extends StatelessWidget {
                   Navigator.push(context, SlideLeftRoute(page: AboutTopic(lesson: courseContent[index])));
                 },
                 child: Card(
-                  color: customLightBlack,
+                  // color: customLightBlack,
                   elevation: 8.0,
                   margin: EdgeInsets.symmetric(horizontal: 10.0, vertical: 5.0),
                   child: ListTile(
@@ -48,19 +47,19 @@ class Lessons extends StatelessWidget {
                         border: Border(
                           right: BorderSide(
                             width: 1.0,
-                            color: Colors.white24
+                            // color: Colors.white24
                           ),
                         ),
                       ),
                       child: Text(
                         (index + 1).toString(),
-                        style: TextStyle(color: Colors.white, fontSize: 18.0),
+                        style: TextStyle( fontSize: 18.0),
                       ),
                     ),
                     title: Text(
                       courseContent[index][0],
                       style: TextStyle(
-                        color: Colors.white,
+                        // color: Colors.white,
                         fontWeight: FontWeight.bold
                       ),
                     ),
@@ -69,7 +68,6 @@ class Lessons extends StatelessWidget {
                         Icon(Icons.linear_scale, color: customPink),
                         Text(
                           " Intermediate",
-                          style: TextStyle(color: Colors.white),
                         ),
                       ],
                     ),
@@ -84,7 +82,6 @@ class Lessons extends StatelessWidget {
     );
 
     return Scaffold(
-      backgroundColor: customDarkBlack, 
       body: body
     );
   }
diff --git a/lib/theme.dart b/lib/theme.dart
new file mode 100644
index 0000000..b1e7bcb
--- /dev/null
+++ b/lib/theme.dart
@@ -0,0 +1,18 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+class ThemeChanger with ChangeNotifier {
+  ThemeData _themeData;
+  bool isLightTheme = false;
+  ThemeChanger(this._themeData);
+
+  getTheme() => _themeData;
+  setTheme(ThemeData theme) {
+    if (theme == ThemeData.dark())
+      isLightTheme = false;
+    else
+      isLightTheme = true;
+    _themeData = theme;
+    notifyListeners();
+  }
+}
diff --git a/pubspec.lock b/pubspec.lock
index 1e11639..6788f87 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -21,42 +21,42 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.3"
+    version: "2.4.2"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.0.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.5"
+    version: "1.0.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.1.3"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.0.1"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.5"
+    version: "1.14.13"
   convert:
     dependency: transitive
     description:
@@ -77,7 +77,7 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -115,14 +115,14 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.3"
+    version: "0.12.8"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.6"
+    version: "1.1.8"
   mime:
     dependency: transitive
     description:
@@ -136,14 +136,21 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.3"
+    version: "1.7.0"
   petitparser:
     dependency: transitive
     description:
       name: petitparser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.0"
+    version: "3.0.4"
+  provider:
+    dependency: "direct main"
+    description:
+      name: provider
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.1+1"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -155,49 +162,49 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.4"
+    version: "1.7.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.6"
+    version: "1.9.5"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.0.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.0.5"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.1.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.6"
+    version: "0.2.17"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.5"
+    version: "1.2.0"
   uuid:
     dependency: transitive
     description:
@@ -211,7 +218,7 @@ packages:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.5"
+    version: "2.0.8"
   xml:
     dependency: transitive
     description:
@@ -234,5 +241,5 @@ packages:
     source: hosted
     version: "7.0.0+7"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.9.0-14.0.dev <3.0.0"
   flutter: ">=1.12.13+hotfix.5"
diff --git a/pubspec.yaml b/pubspec.yaml
index b6186a1..9a09a23 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -25,6 +25,7 @@ dependencies:
     sdk: flutter
   youtube_player_flutter: 
   flutter_launcher_icons: 
+  provider: ^2.0.1
 
 flutter_icons:
   image_path: "assets/icon/icon.png"