#wrapper .logo a {width: 300px; background: url("/siteelements/images/base/logo-businessschool.png") no-repeat !important; display: block;font-size: 0; color: transparent;}

@media only screen and (max-width: 479px) {

       #wrapper .logo a{background-image: url("/SiteElementsHomepage/images/fallback/mobile-logo.png"); background-size: cover!important; width: 77px; height: 77px;}   
       #wrapper .logo img{width: 100%; height: 100%;}

  }