BlazorWebAssembly/App.razor

<CascadingAuthenticationState>
    <Router AppAssembly="@typeof(App).Assembly">
        <Found Context="routeData">
            <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)">
                <NotAuthorized>
                    <div class="p-5 text-center">
                        <h2 class="text-danger">Access Denied</h2>
                        <p>You don't have permission to view this page. Please log in.</p>
                        <a href="/login" class="btn btn-primary mt-3">Go to Login</a>
                    </div>
                </NotAuthorized>
                <Authorizing>
                    <div class="p-5 text-center">
                        <div class="spinner-border text-primary" role="status">
                            <span class="visually-hidden">Loading...</span>
                        </div>
                        <p class="mt-2">Verifying credentials...</p>
                    </div>
                </Authorizing>
            </AuthorizeRouteView>
            <FocusOnNavigate RouteData="@routeData" Selector="h1" />
        </Found>
        <NotFound>
            <PageTitle>Not found</PageTitle>
            <LayoutView Layout="@typeof(MainLayout)">
                <p role="alert">Sorry, there's nothing at this address.</p>
            </LayoutView>
        </NotFound>
    </Router>
</CascadingAuthenticationState>