WL-3714 : Render IE11 'Minimise' text offscreen

The 'Minimise' em text (used for accessibility), which has position:fixed is, as a result,
given display:block in Firefox and Chrome and IE 8,9 but not in IE1, which has display:inline.

Changing it to display:block in IE11 does not seem to make a difference.

This change moves the text offscreen.