#MyLoading {
  z-index: 30;
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  display: none;
}
#MyLoading >div {
  position: absolute;
  padding: 24px 24px;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  color: #000;
  background: translate;
  border-radius: 50%;
  max-height: 90vh;
  overflow: auto;
  border-left: white 0px ridge;
  border-top: white 1px ridge;
  border-right: white 0px ridge;
  border-bottom: white 1px ridge;
}
.back-to-top {
  position: fixed;
  width: 48px;
  height: 48px;
  right: 20px;
  bottom: 20px;
  z-index: 9;
  background-color: rgba(73,143,157,0.6);
  border-radius: 50%;
  color: white;
  text-align: center;
  cursor: pointer;
  display: none !important;
}
.back-to-top i {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  font-size: 24px;
}