design: Style bottom navigation bar in backgroundcolor

lib/config/themes.dart

@@ -60,12 +60,16 @@ abstract class FluffyThemes {
   static const Duration animationDuration = Duration(milliseconds: 250);
   static const Curve animationCurve = Curves.easeInOut;
 
-  static ThemeData buildTheme(Brightness brightness, [Color? seed]) =>
-      ThemeData(
+  static ThemeData buildTheme(Brightness brightness, [Color? seed]) {
+    final colorScheme = ColorScheme.fromSeed(
+      brightness: brightness,
+      seedColor: seed ?? AppConfig.colorSchemeSeed ?? AppConfig.primaryColor,
+    );
+    return ThemeData(
       visualDensity: VisualDensity.standard,
       useMaterial3: true,
       brightness: brightness,
-        colorSchemeSeed: seed ?? AppConfig.colorSchemeSeed,
+      colorScheme: colorScheme,
       textTheme: PlatformInfos.isDesktop || PlatformInfos.isWeb
           ? brightness == Brightness.light
               ? Typography.material2018().black.merge(fallbackTextTheme)
@@ -94,6 +98,8 @@ abstract class FluffyThemes {
           statusBarColor: Colors.transparent,
           statusBarIconBrightness: brightness.reversed,
           statusBarBrightness: brightness,
+          systemNavigationBarIconBrightness: brightness.reversed,
+          systemNavigationBarColor: colorScheme.background,
         ),
       ),
       textButtonTheme: TextButtonThemeData(
@@ -125,6 +131,7 @@ abstract class FluffyThemes {
         ),
       ),
     );
+  }
 }
 
 extension on Brightness {

lib/pages/chat_list/chat_list_view.dart

@@ -176,7 +176,12 @@ class ChatListView extends StatelessWidget {
                     body: ChatListViewBody(controller),
                     bottomNavigationBar: controller.displayNavigationBar
                         ? NavigationBar(
+                            elevation: 4,
                             height: 64,
+                            shadowColor:
+                                Theme.of(context).colorScheme.onBackground,
+                            surfaceTintColor:
+                                Theme.of(context).colorScheme.background,
                             selectedIndex: controller.selectedIndex,
                             onDestinationSelected:
                                 controller.onDestinationSelected,