I went into the Browser Toolbox (Source Docs page) and added this to my existing userChrome.css code (listed in the Style Editor tab) and it switches the positions between the content and the find bar, once I switch from the Style Editor over to the Inspector tab:

/* Move Find bar above content */
.browserContainer > findbar {
    -moz-box-ordinal-group: 0; 
    position: fixed !important; 
    /* Clean up the top and bottom borders */
    border-bottom: 1px solid ThreeDShadow !important;
    border-top: none !important;
}

That isn't floating, though -- it is fixed. What do you mean by floating?

Thank you for your reply. I apologize for the term "floating". I really meant "move to the top of the page". I 've used it for years in the same place in Firefox and probably compared it to other software where I can move it around the page. I compared your .css instructions to mine and they're the same. I even copied yours into my .css file for testing and still don't get the search box. I have disabled all my add-ons and left in the .css file and still no search box. I've tested this in Windows 11 and still no search box. If I remark out the .css instructions, the box will show OK at the botton of the screen. Works fine in Version 106. Thanks for your help. Regards

If I remark out the .css instructions, the box will show OK at the bottom of the screen.

Okay, so Firefox is reading the rule and moving the box, but I guess for some reason it's not expanding when you hit Ctrl+F. I tested on a clean profile with no other userChrome.css rules and it was working fine, so I wonder whether there might be a conflict with another rule in your file?

Nope, that's not it. I remarked out all other userChrome.css instructions and still don't see the box anywhere. I've got a kazillion Firefox changes made through about:config over the years. I have them all documented so I guess I'll have to go through them and maybe find the culprit. I'll live with the box on the bottom for now. Thanks again. Regards

You can try to add a z-index:2147483647 !important; rule.

Nope, z-index:2147483647 !important; doesn't work. Thanks anyway.