nkoehler/mat-video

.hourglass {
  display: inline-block;
  position: relative;
  width: 64px;
  height: 64px;
}

.hourglass:after {
  content: " ";
  display: block;
  border-radius: 50%;
  width: 0;
  height: 0;
  margin: 6px;
  box-sizing: border-box;
  border: 26px solid #fff;
  border-color: #fff transparent #fff transparent;
  -webkit-animation: hourglass 1.2s infinite;
  animation: hourglass 1.2s infinite;
}

@-webkit-keyframes hourglass {
  0% {
    -webkit-transform: rotate(0);
    -webkit-animation-timing-function: cubic-bezier(0.55, 0.055, 0.675, 0.19);
  }
  50% {
    -webkit-transform: rotate(360deg);
    -webkit-animation-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
  }
  100% {
    -webkit-transform: rotate(720deg);
  }
}

@keyframes hourglass {
  0% {
    transform: rotate(0);
    animation-timing-function: cubic-bezier(0.55, 0.055, 0.675, 0.19);
  }
  50% {
    transform: rotate(360deg);
    animation-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
  }
  100% {
    transform: rotate(720deg);
  }
}