Is there a way to create a fade-in/fade-out effect using CSS 3 only?
.box{
    opacity: 0.0;
    -webkit-transition: 0.5s all;
    -moz-transition: 0.5s all;
}

.box:hover{
    opacity: 1.0;
}

div
{
   transition: width 2s;
   -moz-transition: width 2s; /* Firefox 4 */
   -webkit-transition: width 2s; /* Safari and Chrome */
   -o-transition: width 2s; /* Opera */
}