Fixed navigation bar in Hayden template with banner image and text suppressed

Site URL: https://www.fairfaxbible.org/sermons-2/2020/11/2/spiritual-fruit-patience-1-thessalonians-514

Hi There,

We use the Hayden template and I'm trying to *just* suppress the banner image and blog post titles in blog posts. I discovered a code for this, but now my navigation bar, which is normally transparent on top of banner images has disappeared, or rather it remains transparent. Is there a way I can force the navigation to be non-transparent and appear at the top? Also, if there is a better/more clear cut code for what I'm trying to accomplish, I'd be open to that as well! Here's the code I injected into just our blog header: 

<style>
  .banner-thumbnail-wrapper figure {
    opacity: 0;
}
  .collection-type-blog.view-item .banner-thumbnail-wrapper {
    display: none;
}

</style>