.top_but {
    display: none;
    position: fixed;
    bottom: 50px;
    right: 50px;
    width: 50px;
    height: 50px;
    border-radius: 100%;
    background: url('../images/up.png') no-repeat center center;
    box-shadow: 3px 5px 5px 0px rgba(0,0,0,0.3);

}
.top_but:hover {
    cursor: pointer;
    opacity: .95;
}
.top_but--blue {
    background-color: #015a80;
}
.top_but--red {
    background-color: #800101;
}
.top_but--green {
    background-color: #098001;
}
.top_but--pure {
    background-color: #5b0180;
}

/* Extra Small Devices, Phones */
@media only screen and (max-width : 480px) {
    .top_but {
        left: 50%;
        top: 60px;
        width: 35px;
        height: 35px;
        margin-left: -17px;
        background-image: url('../images/up_small.png');
        box-shadow: 2px 3px 3px 0px rgba(0,0,0,0.3);
    }
}