#scroll-to-top {
  position: fixed;
  z-index: 2147483647;
  bottom: 20px;
  right: 20px;
  color: rgba( 102,153,255,0.6 );
  font-size: 12px;
  font-family: sans-serif;
  text-decoration: none;
  border-radius: 2px;
}
#scroll-to-top:hover {
  position: fixed;
  z-index: 2147483647;
  bottom: 20px;
  right: 20px;
  color: rgba( 102,153,255,0.8 );
  font-size: 12px;
  font-family: sans-serif;
  text-decoration: none;
  border-radius: 2px;
}
.scroll-to-top-not-display{
 display: none;
}