sticky top bar - accommodating the admin menu bar

Hi,

I wanted to make the top bar sticky, so I've added the CSS from this post. It works perfectly when I'm logged out, but when I'm logged in, the top bar sits behind the admin menu.

Is there a way to accommodate the height of the admin bar when logged in, that doesn't affect the site to logged out users?

Thanks

Duncan

https://bc.ryedalewebdesign.com/