如何在Bootstrap表中输入文件旁的列中定位按钮

<table class="table">
  <thead>
    <tr>
      <th>文件名</th>
      <th>操作</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>
        <input type="file" id="fileInput1">
      </td>
      <td>
        <div class="col-md-2">
          <button class="btn btn-primary">上传</button>
        </div>
      </td>
    </tr>
    <tr>
      <td>
        <input type="file" id="fileInput2">
      </td>
      <td>
        <div class="col-md-2">
          <button class="btn btn-primary">上传</button>
        </div>
      </td>
    </tr>
  </tbody>
</table>

<style>
  #fileInput1,
  #fileInput2 {
    position: relative;
  }

  .col-md-2 {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 100px; /* 调整按钮与文件输入列的距离 */
    margin: auto;
  }
</style>