如何将datatable放在中间而不占据整个宽度

.container {
  display: flex;
  justify-content: center;
}

<div class="container">
  <table class="table">
    <!-- datatable内容 -->
  </table>
</div>

<div id="datatable-container">
  <table id="datatable">
    <!-- datatable内容 -->
  </table>
</div>

<script>
  var container = document.getElementById('datatable-container');
  var datatable = document.getElementById('datatable');
  var containerWidth = container.offsetWidth;
  var datatableWidth = datatable.offsetWidth;
  var leftMargin = (containerWidth - datatableWidth) / 2;
  datatable.style.marginLeft = leftMargin + 'px';
</script>