如何垂直对齐一个较小的材质浮动按钮？

.button {
  background-color: #007bff;
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  position: fixed;
  bottom: 20px;
  right: 20px;
}

.container {
  display: flex;
  align-items: center;
}

.container {
  position: relative;
}

.button {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

<div class="container">
  <!-- 其他内容 -->
  <button class="button">按钮</button>
</div>