.UIBackTopTopControl {
    position: fixed;
    bottom: 10px;
    right: 15px;
    background-color: rgba(0, 0, 0, 0.42);
    z-index: 10;
    width: 48px;
    height: 48px;
    border-radius:1000px;
    color:#fff;
    font: normal normal normal 30px/44px FontAwesome;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-align: center;
}
.UIBackTopTopControl:before {
    content: "\f106";
}