@keyframes spinner {
  to {transform: rotate(360deg);}
}

.spinner {
  position: relative;
  min-height: 100px;
}

.spinner:before {
  content: '';
  box-sizing: border-box;
  position: absolute;
  top: 25%;
  left: 50%;
  width: 60px;
  height: 60px;
  margin-top: -10px;
  margin-left: -10px;
  border-radius: 50%;
  border: 5px solid $white;
  border-top-color: $red;
  animation: spinner .75s linear infinite;
  z-index: $zindex-modal-backdrop;
}