如何在Bootstrap中将div垂直对齐到中心？

<div class="d-flex justify-content-center align-items-center" style="height: 100vh;">
  <div>内容</div>
</div>

<div class="d-flex align-items-center" style="height: 100vh;">
  <div class="mx-auto">内容</div>
</div>

<div style="position: relative; height: 100vh;">
  <div style="position: absolute; top: 50%; transform: translateY(-50%);">内容</div>
</div>