app-layout not on top of content

I’m having a problem with [app-layout]
( When I scroll down the page, app-layout is “sticky” as it might be supposed to be, but the problem is that it is below every other content. I tried to play with z-index but it has no effect.

Using VerticalLayout and components are added like so:

add(appLayout, hakukenttaDiv, osallistujagrid, kilpailugrid);

Attached some images.

I didn’t realize content should be added into appLayout. Fully working now.