Have you tested this on mobile safari? It jumped around a lot before sort of displaying ok, but then the jumping issues returned. I query it because your page m

Have you tested this on mobile safari? It jumped around a lot before sort of displaying ok, but then the jumping issues returned. I query it because your page makes a point of mentioning the fully responsive layout - but personally if I visited a page which displayed the behaviour on mobile like yours did, I would immediately leave and not come back.