.desktop-nav .sub-menu {
 opacity: 0;
}
.desktop-nav li:hover .sub-menu {
 opacity: 1;
 animation-duration: 1s;
 animation-name: fade-in;
 -moz-animation-duration: 1s;
 -moz-animation-name: fade-in;
 -webkit-animation-duration: 1s;
 -webkit-animation-name: fade-in;
}
@keyframes fade-in {
 0% {display: none; opacity: 0;}
 100% {display: block; opacity: 1;}
}
@-moz-keyframes fade-in {
 0% {display: none; opacity: 0;}
 100% {display: block; opacity: 1;}
}
@-webkit-keyframes fade-in {
 0% {display: none; opacity: 0;}
 100% {display: block; opacity: 1;}
}