#scrollUp {
background: none repeat scroll 0 0 #333;
border-radius: 10px;
bottom: 20px;
color: #fff;
font-size: 30px;
opacity: 0.5;
padding: 7px 12px;
right: 20px;
-webkit-transition:  1s;
-moz-transition:  1s;
-o-transition:  1s;
transition:  1s;
outline: none;
}
a#scrollUp:hover{color:#fff;opacity: inherit;}