.on('mouseenter focusin', function() method which is working nicely. Out of intuition, I also used .on('mouseleave focusout', function() for its "reverse" - that's the one which did not work. The apparent reason being that it's listening to EITHER mouseleave OR focusout. So assuming we clicked on a link to gain a focus state, the highlighter doesn't retain itself, since the mouseleave event is fired despite the element being still on focus state.