/**
 * back-to-top button
*/
.page-top {
    text-align: center;
    display: inline-block;
    height: 40px;
    width: 40px;
    line-height: 40px;
    position: fixed;
    bottom: 40px;
    right: 10px;
    padding: 0;
    border: none;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
    overflow: hidden;
    white-space: nowrap;
    visibility: hidden;
    opacity: 0;
    transition: opacity .3s 0s, visibility 0s .3s;
}
.page-top.visible,
.page-top.fade-out {
    transition: opacity .3s 0s, visibility 0s 0s;
}
.page-top.visible {
    visibility: visible;
    opacity: 1;
}
.page-top.fade-out {
    /* if the user keeps scrolling down, the button is out of focus and becomes less visible */
    opacity: .5;
}
.page-top span:before{
    display: inline-block;
    font-weight: 900;
    color: white;
}
.page-top:hover{
    opacity: 1;
}
@media only screen and (min-width: 1024px) {
    .page-top {
    height: 60px;
    width: 60px;
    right: 30px;
    bottom: 30px;
    }
    .page-top span:before{
        line-height: 60px;
    }
}