.back-to-top {
    cursor: pointer;
    position: fixed;
    bottom: 20px;
    right: 20px;
    display:none;
}

/* unvisited link */
a.li:link {
  color: white;
}

/* visited link */
a.li:visited {
  color: white;
}

/* mouse over link */
a.li:hover {
  color: black;
}

/* selected link */
a.active {
  color: black;
}