Html 如何设置弹性盒子容器的具体大小

正如标题所述，我希望Flexbox的容器具有特定的宽度和高度.然而，我不知道我可以使用什么方法.这是我的代码:

<div class="container-gallery">
  <img src="gallery/img.png" alt="">
  <img src="gallery/img1.jpg" alt="">
  <img src="gallery/img2.jpg" alt="">
  <img src="gallery/img3.jpg" alt="">
  <img src="gallery/img4.jpg" alt="">
  <img src="gallery/img5.jpg" alt="">
</div>

.container-gallery {
  display: flex;
  flex-wrap: wrap;
  /* width: 67.5%; */
  justify-content: center;      
}

.container-gallery img{
  width: 15%;
  height: 30vh;
  border-radius: 8%;
  margin: 1%;
}

我try 创建容器图库的父项div以使子项div居中，并在容器图库中放置特定的宽度.它确实可以工作；但是，当您try 调整它的大小时，它不会将其内容居中，因为它设置了宽度.大概是这样的:

<div class="container-gallery">
  <img src="gallery/img.png" alt="">
  <img src="gallery/img1.jpg" alt="">
  <img src="gallery/img2.jpg" alt="">
  <img src="gallery/img3.jpg" alt="">
  <img src="gallery/img4.jpg" alt="">
  <img src="gallery/img5.jpg" alt="">
</div>

.container-gallery {
  display: flex;
  flex-wrap: wrap;
  width: 67.5%;
}

.container-gallery img{
  width: 15%;
  height: 30vh;
  border-radius: 8%;
  margin: 1%;
}

.main-gallery {
  display: flex;
  justify-content: center;
}

What can I do?
I'm pretty new to Flexbox so treat this as a newbie question.

It should be like this! the width and height.