Make interior menu sticky

Does anyone know how I can make the only the interior page menus sticky?

Did you mean that you want the top menu to be sticky? if so, you can manage it from customize > header area > menu style.

Sorry, I am actually looking for the main home page menu to be sticky, but the interior menu pages to be static.

I want my homepage to stay the same as it is here:

but I would like the interior page menus to function like this:

I see, so you want the page menu to keep sticky but without having transparent background color, is it correct?

if so, you can add this css code below using custom css plugin:

.site-header {
    background-color: rgba(51,46,25,0.9);

.site-header.float-header {
    padding-top: 20px;