Adding items to the top bar

The task here is to add icons and menu elements to the top-bar menus on my page layout.

This page is an experiment in how this works (or rather doesn't). So far I have got a working solution on the Shopping Cart page.
The workaround has the mobile screen with the cart icon followed by tempusfugit.me.uk.

I don't really understand what is going on here and I suspect that there is a case of some of the classes not working well together. I will leave this as it is and come back to it if I have any more thoughts.

The code is different to that on the Shopping Cart page and is likely to be so as I work on the problem.