@media only screen and (min-width: 615px){
    .scrollup {height: 50px;width: 50px;opacity:0;padding:10px;border-radius:25px;
               text-align:center;background: #224433;font-weight:bold;z-index: 100;color:#444;
               text-decoration:none;position:fixed;bottom: 20px;left:20px;
               transition:opacity 1s ease-in;}
    .scrollup.visible {opacity:1;}

    .glyphicon-arrow-up{color: white; font-size: 25px; left: -1px; top: 2px !important;}
}

@media only screen and (max-width: 615px){
    .scrollup {height: 50px;width: 50px;opacity:0;padding:10px;border-radius:25px;
               text-align:center;background: #224433;font-weight:bold;z-index: 100;color:#444;
               text-decoration:none;position:fixed;bottom: 10px;left:10px;
               transition:opacity 1s ease-in;}
    .scrollup.visible {opacity:1;}

    .glyphicon-arrow-up{color: white; font-size: 25px; left: -1px; top: 2px !important;}
}