<section id="wrapper">
<div id="anime_test">
</div>
<br>
<div class="push-btn" onclick="clickTest();">
    PUSH
</div>
</section>

#wrapper {
  display: block;
  width:100%;
  text-align:center;
  margin:30px auto;
}
#anime_test{
    height: 100px;
    width: 100px;
    background-color: #366cf4;
    position: relative;
    left: 50px;
    transition: 2.5s;
    border-radius: 1.5rem;
}

#anime_test.active {
    background-color: #0435b0;
    left: calc(100% - 150px);
    border-radius: 3.5rem;
}

.anime_test-btn {
    margin-top:  10px;
    display:  inline-block;
    padding:  5px 10px;
    border: solid 1px;
    cursor:  pointer;
}


.push-btn {
  font-size: 1.0rem;
  font-weight: 700;
  line-height: 1.5;
  position: relative;
  display: inline-block;
  padding: 0.5rem 2rem;
  cursor: pointer;
  text-align: center;
  vertical-align: middle;
  letter-spacing: 0.1em;
  color: #fff;
  border-radius: 0.5rem;
  background-color: #eb6100;
}

function clickTest() {
      target = document.getElementById("anime_test");
      if (target.className == null || target.className=="") {
        target.className = "active";
      } else {
        target.className = "";
      }
    }