Creating a transparent homepage header with solid bar interior headers

Hi everybody.

I'm working on a site with a dark homepage banner image that allows for the logo/nav/social to "float" in the header on top of it, and I can achieve this effect easily enough by setting the Header: Layout settings to "bottom".  For the interior pages, however, the banner images are not able to accommodate the logo/nav/social so I would like to have that content contained in a visible header bar, with the banner image beneath.

I've looked through the forums here and found things that are similar to what I'm looking for, but not quite. I tried to execute something from a forum that used both JS and CSS, but it was trying to accomplish slightly different things. It didn't seem to have any effect, and I'm sure I messed something up along the way. I'm using some custom coding on this site, but I don't have a lot of experience with it. Hoping there's a relatively simple solution or, failing that, a complex one that's relatively easy to replicate on this site.

Thanks in advance for any insight you might be able to offer,
Michael

can you share link to your site? We can help easier.