CSS only shimmer

shimmer.css

@keyframes placeHolderShimmer {
  0% {
    background-position: -80px 0;
  }

  100% {
    background-position: 640px 0;
  }
}

.u-placeholder-shimmer {
  pointer-events: none;
  color: transparent;
  animation-duration: 1.25s;
  animation-fill-mode: forwards;
  animation-iteration-count: infinite;
  animation-name: placeHolderShimmer;
  animation-timing-function: linear;
  background-color: #f6f6f6;
  background-image: linear-gradient(to right, #f6f6f6 0%, #eeeeee 50%, #f6f6f6 100%);
  background-size: 80px 100%;
  background-repeat: no-repeat;
  background-position: 0 0;
  border-radius: 0.25em;
}

.u-placeholder-shimmer * {
  color: transparent !important;
  border-color: transparent !important;
  background: transparent !important;
  box-shadow: none !important;
  text-shadow: none !important;
}