html - 绝对容器中的 CSS flex 布局

Question

我有以下 HTML/CSS，其中包含一个具有绝对高度的容器 (.full-width.section3)。但是，将内容居中是行不通的。由于我是 flex 模型的新手，有人可以向我解释一下，为什么三个子 div 不是垂直居中的吗？

body {
  margin:0;
  
}
.container {
  display:flex;
  flex-wrap:wrap;     
  height:100vh;
  background-color: white;
}
.full-width {
  width:100%;              
}

.full-width.section3{
	height: 795px;
}

.full-width > .content > .third-parent{
  height: 100%;
  display: flex;
}

.full-width > .content > .third-parent > .third{
  position: relative;
  flex: 1 1 0px;
  width: 100%;
  border: 1px solid black;
}

.full-width > .content > .third-parent > .third > img{
  position: absolute;
  width: 100%;
  height: auto;
  left: 50%;
  top:50%;
  visibility: visible;
  text-align: center;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.middle-text{
  position: absolute;
  width: 100%;
  left: 50%;
  top:50%;
  visibility: visible;
  text-align: center;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}


.full-width > .content > .third-parent > .third > .middle-text > .list-div2{
    display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
}

.full-width > .content > .third-parent > .third > .middle-text > .list-div2  li{
   position: relative;
  display: block;
  margin-bottom: 5px;
  padding: 10px;
  text-align: left;
  text-transform: uppercase;
  visibility: visible;
}

.list-div2 li::before{
  content: '\2022';
  margin-right: 10px;
}
.items-list2 {
  margin: 0;
  padding: 0;
}

<div class="container">
<div class="full-width section3">
    <div class="content">
       <div class="third-parent">
         <div class="third" id="one">
           <img src="https://fakeimg.pl/350x200/?text=right">
          </div>
        <div class="third" id="two">
          <div class="middle-text">
            <h1>Some headline</h1>
                  <div class="list-div2">
        <ul class="items-list2" id="list">
          <li>Entry A</li>
          <li>Entry B</li>
          <li>Entry C</li>
          <li>Entry D</li>
        </ul>
      </div>
          </div>
        </div>
        <div class="third" id="three">
          <img src="https://fakeimg.pl/350x200/?text=left">
        </div>
         </div>
       </div>
</div>
</div>

Answer 1

您将 flex 与绝对定位混合在一起。这会破坏子元素的 flex :

As it is out-of-flow, an absolutely-positioned child of a flex container does not participate in flex layout.

来源:https://www.w3.org/TR/css-flexbox-1/#abspos-items