body {
}
#aGoTop {
    position: fixed;
    right: 50px;
    bottom: 50px;
    display: block;
    width: 60px;
    height: 60px;
    background: #FFF;
    border-radius: 50%;
    text-indent: -9999px;
    z-index: 1;
    cursor: pointer;
}

    #aGoTop:before {
        content: "";
        position: absolute;
        left: 50%;
        top: 50%;
        display: block;
        width: 0;
        height: 0;
        margin: -7px 0 0 -10px;
        border-style: solid;
        border-width: 0 10px 15px 10px;
        border-color: transparent transparent #333 transparent;
    }