How to create mega menu with pure css

I have query i want to create a mega menu with pure css3 no jquery Please suggest how i can achieve that or any reference?

I have a main navigation for example :

     Home   AboutUs   Shop 
                      Women
                      Gents
                      Kids 

I have done with the above one ,Now I want when user take mouse over 'WOMEN' submenu then ON left side horizontal menu will display that three columns with link(like on cart site we generally see )

for more info visit here http://ift.tt/1EvEKDa

Here as user click on 'clothing' a mega menu(same i want ) come with differ columns

Same I need but only when user mouse hover 'Women' sub menu that i show above

NO frame work no jquery Pure css that i need to use

If any one have any reference then please help and share with me

Thanks