.video-play-button {
    position: absolute;
    z-index: 10;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
    box-sizing: content-box;
    display: block;
    width: 15px;
    height: 12px;
    background: #3ab5bf;
    border-radius: 50%;
    padding: 9px 24px 18px 28px;
}
.video-play-button:before {
    content: "";
    position: absolute;
    z-index: 0;
    left: 50%;
    top: 50%;
    transform: translateX(-50%) translateY(-50%);
    display: block;
    width: 150px;
    height: 150px;
    background: #3ab5bf;
    border-radius: 50%;
    animation: pulse-border 1500ms ease-out infinite;
}

.video-play-button:after {
    content: "";
    position: absolute;
    z-index: 1;
    left: 50%;
    top: 50%;
    transform: translateX(-50%) translateY(-50%);
    display: block;
    width: 70px;
    height: 70px;
    background: #3ab5bf;
    border-radius: 50%;
    transition: all 200ms;
    border: solid 4px #fff;
}


.video-play-button span {
    display: block;
    position: relative;
    z-index: 3;
    width: 0;
    height: 0;
    border-left: 18px solid #fff;
    border-top: 10px solid transparent;
    border-bottom: 12px solid transparent;
}

@keyframes pulse-border {
  0% {
    transform: translateX(-50%) translateY(-50%) translateZ(0) scale(1);
    opacity: 1;
  }
  100% {
    transform: translateX(-50%) translateY(-50%) translateZ(0) scale(1.5);
    opacity: 0;
  }
}