> Block-level in what sense? <img> is not block-level in any sense; One > could argue that <video> and <object> are "block-level" in HTML terms, > but it's context-dependent (they can contain blocks if their parent > can). None of these are block-level in the CSS sense, by default.
True, but surely saying "any element" opens the door to full-screening inline text elements (e.g <span> elements). Looking at a few lists of all inline elements in HTML, there aren't any except <img> (except perhaps form inputs/textareas) that should obviously be permitted this sort of full-screen capability (without first being defined as "display: block"). I suppose the native style being "position: fixed" would put those elements in a block formatting context anyway, but what implications might that have for things like table cells/table rows being made full-screen? —Kit