Two RadzenSidebar side by side

Hello there,
I would like to put two sidebar side by side with the second one collapsible, I have therefor tried to the define the layout as it follows:

<RadzenLayout class="rz-shadow-0 sam-background" Style="grid-template-areas: 'rz-sidebar rz-right-sidebar rz-header' 'rz-sidebar rz-right-sidebar rz-body'">

and then the second sidebar:

<RadzenSidebar @bind-Expanded="@sidebarExpanded" class="rz-shadow-1 sam-sidebar" Style="rz-right-sidebar">

but the two sidebars are overlaid and by inspecting the page it seems that grid of the layout contains only two colums.
What did I do wrong?