Beating heart animation

heart.html

<!--
From https://ackee.electerious.com/
-->

<style>
.heart {
  width: 16px;
  height: 16px;
  fill: #73fac8;
  margin: 0 4px -1px;
  -webkit-animation: heart 1s linear infinite;
  animation: heart 1s linear infinite;
}

@-webkit-keyframes heart {
 0% {
  transform:scale(1)
 }
 14% {
  transform:scale(1.2)
 }
 28% {
  transform:scale(1)
 }
 42% {
  transform:scale(1.2)
 }
 70% {
  transform:scale(1)
 }
}
@keyframes heart {
 0% {
  transform:scale(1)
 }
 14% {
  transform:scale(1.2)
 }
 28% {
  transform:scale(1)
 }
 42% {
  transform:scale(1.2)
 }
 70% {
  transform:scale(1)
 }
}
</style>

<svg class="heart">
  <use xlink:href="#heart">
    <symbol id="heart" viewBox="0 0 20 18">
        <g transform="translate(-2 -3)">
            <path d="m13.35 20.13c-.76.69-1.93.69-2.69-.01l-.11-.1c-5.25-4.75-8.68-7.86-8.55-11.74.06-1.7.93-3.33 2.34-4.29 2.64-1.8 5.9-.96 7.66 1.1 1.76-2.06 5.02-2.91 7.66-1.1 1.41.96 2.28 2.59 2.34 4.29.14 3.88-3.3 6.99-8.55 11.76z"></path>
        </g>
    </symbol>
  </use>
</svg>