[tsigel]

<style>

  .block.moved {
    left: 200px;
  }

 .block {
     background: red;
     width: 20px;
     height: 20px;
     position: absolute;
     left: 0;
     top: 35px;
     transition: left 1s ease;
     -webkit-transition: left 1s ease;
     -moz-transition: left 1s ease;
     -o-transition: left 1s ease;
     -ms-transition: left 1s ease;
  }

</style>

<a>Двигать</a>
<div class="block"></div>

<script>

document.querySelector("a").addEventListener("click", function () {
  document.querySelector(".block").classList.toggle("moved");
}, false);

</script>