CSS Animation Trick to save state

HTML

<div class="vh">
            <div class="sk-spinner sk-spinner-wave">
                <div class="sk-rect1"></div>
                <div class="sk-rect2"></div>
                <div class="sk-rect3"></div>
                <div class="sk-rect4"></div>
                <div class="sk-rect5"></div>
            </div>

    </div>

CSS

/*
 *  Usage:
 *
 *    <div class="sk-spinner sk-spinner-wave">
 *      <div class="sk-rect1"></div>
 *      <div class="sk-rect2"></div>
 *      <div class="sk-rect3"></div>
 *      <div class="sk-rect4"></div>
 *      <div class="sk-rect5"></div>
 *    </div>
 *
 */

.sk-spinner-wave.sk-spinner {
    font-size: 10px;
    height: 30px;
    margin: 0 auto;
    text-align: center;
    width: 50px;
}

.sk-spinner-wave div {
    -webkit-animation: sk-waveStretchDelay 1.2s infinite ease-in-out;
    animation: sk-waveStretchDelay 1.2s infinite ease-in-out;
    background-color: #1ab394;
    display: inline-block;
    height: 100%;
    width: 6px;
}

.sk-spinner-wave .sk-rect2 {
    -webkit-animation-delay: -1.1s;
    animation-delay: -1.1s;
}

.sk-spinner-wave .sk-rect3 {
    -webkit-animation-delay: -1s;
    animation-delay: -1s;
}

.sk-spinner-wave .sk-rect4 {
    -webkit-animation-delay: -0.9s;
    animation-delay: -0.9s;
}

.sk-spinner-wave .sk-rect5 {
    -webkit-animation-delay: -0.8s;
    animation-delay: -0.8s;
}

@-webkit-keyframes sk-waveStretchDelay {
    0%,
    40%,
    100% {
        -webkit-transform: scaleY(0.4);
        transform: scaleY(0.4);
    }

    20% {
        -webkit-transform: scaleY(1);
        transform: scaleY(1);
    }
}

@keyframes sk-waveStretchDelay {
    0%,
    40%,
    100% {
        -webkit-transform: scaleY(0.4);
        transform: scaleY(0.4);
    }

    20% {
        -webkit-transform: scaleY(1);
        transform: scaleY(1);
    }
}
body, html {
  box-sizing:border-box;
  height:100%;
  margin:0;
}
.vh {
    background-color: #fff;
    height: 100%;
    align-items: center;
    display: flex;
}
.vh > div {
    width: 100%;
    text-align: center;
    vertical-align: middle;
}