<div class="center">
  <div id="control">
    <div class="border"></div>
    <div class="play"></div>
  </div>
</div>

body {
  background: #333;
}

div.center{
  position:absolute;
  top:50%;
  left:50%;
  transform:translate(-50%, -50%);
}

#control {
  position: absolute;
  bottom: 10px;
  width: 20px;
  height: 20px;
  right: 10px;
  cursor: pointer;

  .border {
    width: 100%;
    height: 100%;
    border: 1px solid #41fff5;
    border-radius: 20px;
  }

  &.is--playing .border {
    border-top: none;
    border-bottom: none;
    animation: spin 1.5s ease-in-out infinite;
  }

  .play {
    position: absolute;
    top: 6px;
    left: 9px;
    box-sizing: border-box;
    height: 7px;
    width: 5px;

    border-color: transparent transparent transparent #41fff5;
    transition: 100ms all ease;
    will-change: border-width;
    cursor: pointer;

    // play state
    border-style: solid;
    border-width: 5px 0 5px 5px;
  }
  &.is--playing .play {
    border-style: double;
    border-width: 0px 0 0px 6px;
    transform: translate(-1px, 1px);
  }
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

var playButton = document.getElementById('control');

playButton.addEventListener('click', e => {
  e.preventDefault();
  playButton.classList.toggle('is--playing');
});