JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<!-- Button trigger modal -->
<button type="button" class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
  <div class="modal-dialog-wrap">
    <div class="modal-dialog" role="document">
      <div class="modal-content">
        <div class="modal-header">
          <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
          <h4 class="modal-title" id="myModalLabel">Modal title</h4>
        </div>
        <div class="modal-body">
          ...
        </div>
        <div class="modal-footer">
          <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
          <button type="button" class="btn btn-primary">Save changes</button>
        </div>
      </div>
    </div>
  </div>
</div>

CSS

.modal-dialog-wrap {
  display: table;
  table-layout: fixed;
  width: 100%;
  height: 100%;
}

.modal-dialog {
  display: table-cell;
  vertical-align: middle;
  text-align: center;
}

.modal-content {
  display: inline-block;
  text-align: left;
}