feat: pure black theme

Closes #254

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/pages/video/detail/reply/widgets/reply_item_grpc.dart

@@ -160,8 +160,7 @@ class ReplyItemGrpc extends StatelessWidget {
             indent: 55,
             endIndent: 15,
             height: 0.3,
-            color:
-                Theme.of(context).colorScheme.onInverseSurface.withOpacity(0.5),
+            color: Theme.of(context).colorScheme.outline.withOpacity(0.08),
           )
       ],
     );