Changed links to chapters, button to synchronize chapters from courses list, dark mode.

app/Http/Controllers/CourseController.php

@@ -16,11 +16,11 @@ class CourseController extends Controller
         return view('course.index', compact('course'));
     }
 
-    public function sync(Course $course)
+    public function sync(Course $course): \Illuminate\Http\RedirectResponse
     {
         $course->chapters->each->update(['sync_offline' => 1]);
         $course->chapters->each(fn($chapter) => DownloadVideoFile::dispatch($chapter->id));
-        return redirect(route('course.index', ['course' => $course]));
+        return redirect()->back();
     }
 
 }