.element {
    height: 20%;
    width: 20%;
    margin: 0 auto;
    animation-name: stretch;
    animation-duration: .333s;
    animation-timing-function: ease-out;
    animation-delay: 0;
    animation-iteration-count: infinite;
    animation-fill-mode: none;
    animation-play-state: running;
    border-radius: 100%;
    background: radial-gradient(circle at 100px 100px, white, purple);
    border: 4px pink solid;
  }

  @keyframes stretch {
    0% {
      transform: scale(.1);
    }
    30% {
      transform: scale(.9);
    }
    100% {
        transform: scale(.1);
    }
  }

  body,
  html {
    height: 100%;
  }

  body {
    display: flex;
    align-items: center;
    justify-content: center;
  }