Loading Effect

.loading-spinner {
  width: 5.5em;
  height: 5.5em;
  border: none;
  background-color: transparent;
  font-size: 1.5em;
  color: #333;
  overflow: hidden;
  border-radius: 50%;
  -webkit-mask-image: linear-gradient(transparent 50%, var(--black) 50%), linear-gradient(to right, transparent 50%, var(--black) 50%);
  mask-image: linear-gradient(transparent 50%, var(--black) 50%), linear-gradient(to right, transparent 50%, var(--black) 50%);
  animation: loading-spinner-mask 6s infinite cubic-bezier(.3, .6, 1, 1);
}

.loading-spinner::before {
  content: "";
  display: block;
  width: 100%;
  height: 100%;
  border: solid .357em currentColor;
  border-right-color: transparent;
  background-color: transparent;
  border-radius: 50%;
  animation: loading-spinner .75s infinite linear alternate;
}

:-ms-lang(x), .loading-spinner::before {
  /* hack for IE11 */
  animation: none;
}

@keyframes loading-spinner-mask {
  0% {
    transform: rotate(0deg);
  }
  12.5% {
    transform: rotate(180deg);
  }
  25% {
    transform: rotate(630deg);
  }
  37.5% {
    transform: rotate(810deg);
  }
  50% {
    transform: rotate(1260deg);
  }
  62.5% {
    transform: rotate(1440deg);
  }
  75% {
    transform: rotate(1890deg);
  }
  87.5% {
    transform: rotate(2070deg);
  }
  100% {
    transform: rotate(2520deg);
  }
}
@keyframes loading-spinner {
  0% {
    border-top-color: currentColor;
    border-bottom-color: transparent;
    border-left-color: transparent;
    transform: rotate(-30deg);
  }
  29.4% {
    border-left-color: transparent;
  }
  29.41% {
    border-left-color: currentColor;
  }
  64.7% {
    border-bottom-color: transparent;
  }
  64.71% {
    border-bottom-color: currentColor;
  }
  100% {
    border-bottom-color: currentColor;
    border-left-color: currentColor;
    transform: rotate(225deg);
  }
}