#header{overflow:hidden;top:0;left:0;-webkit-transition:height .3s;-moz-transition:height .3s;-ms-transition:height .3s;-o-transition:height .3s;transition:height .3s}#main_menu li,#site_logo img{-webkit-transition:all .3s;-moz-transition:all .3s;-ms-transition:all .3s;-o-transition:all .3s;transition:all .3s}