We're building a web app, to be used on tablet devices predominantly, but desktop too.
We have menu items at the top of the page that have children, I've been told that for good accessibility reasons that it's better to push content down when tapping to show the menu, but a lot of sites still use hover states that 'absolutely' cover content.
This latter functionality would cover content and not allow the user to see content until the menu item is closed. However pushing content down alleviates any potential problems with JS failures etc, still allowing the user to scroll to the content. A good example of pushing content down is the 'more' menu item of tfl or the 'more' section on bbc.co.uk
So my question is - hover over or push content down? What's the best practice for accessibility?