Slider size

Hi Sakin, I want to reduce the size of the slider on 'Full Frame' after viewing other support forums I have taken your previous advise and added the following to the custom css. but nothing has happened. Any suggestions would be appreciated. /* For Screen size minimum 769px */ @media screen and (min-width: 769px) { #main-slider .featured-img { float: center; width: 75%; } } Thanks in advance Ita