.btn-preview {
  position: fixed;
  width: 3.428571rem;
  height: 3.428571rem;
  border-radius: 50%;
  background-color: #FF8A62;
  line-height: 3.428571rem;
  text-align: center;
  color: #fff;
  font-size: 1.071429rem;
  font-weight: 700;
  right: 0.928571rem;
  bottom: 15.714286rem;
  z-index: 999;
}