I doubt if this is what you are after but I have a shape (not a NavBar), which is 690px width (the Red one), centred and with a Name of htmlclass="fixed".
My head code is:
Code:
<style>.fixed {
position: fixed;
margin-left: calc(50vw - 690px);
}
</style>
It is now "sticky" with other objects scrolling over it.
I tried adding "fixed" to a Navbar but it still moves and adding Xara's Sticky (the Green shape) doesn't work.
Preview with a short height window to see things in action:
CSS - Fixed Under-Shape.xar
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