> Not necessarily. What if the un-visited box was set to display:none? Then it would remain 'none' for the visited box too. Messing with 'display' is disabled

> Not necessarily. What if the un-visited box was set to display:none? Then it would remain 'none' for the visited box too. Messing with 'display' is disabled in 'visited' to prevent this class of workarounds.