Roots Discourse

Sticky top on navbar being pushed off by "uncle" blade

I’m applying sticky top to my nav tag in nav blade and it works as I scroll over the banner image (sibling to nav tag), but when I scroll past the end of the header tag and into the document div the navbar is pushed off the screen.

Hierarchy

header blade
    navigation blade containing nav with sticky top-0
    banner image
/header
div
    rest of content
/div

If I apply sticky top to header blade the whole header section stays sticky over the rest of the page, but I don’t want this to include the banner image. What can I do?