为什么我的 div 没有占据其父容器的 100% 高度？

Question

这里有点混乱。我很累，所以我确定我犯了一个愚蠢的错误，但这是我的 HTML/CSS:

.CAContainer {
  display: flex;
  flex-flow: row nowrap;
  justify-content: flex-start;
  align-items: center;
  margin: 0;
  padding: 0;
}
.CASideBorder {
  height: 100%;
  background: #000;
  width: 8px;
}
.CAMiddleContainer {
  display: flex;
  flex-flow: column nowrap;
  justify-content: center;
  align-items: center;
}
.CATopBorder {
  height: 8px;
  background: #000;
  width: 100%;
}
.CAMiddleTextContainer {
  padding: 40px 80px 40px 80px;
  font-size: 4em;
  color: #000;
}
.CABottomBorderContainer {
  display: flex;
  flex-flow: row nowrap;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  height: 8px;
}
.CABottomBorderLeft,
.CABottomBorderRight {
  flex: 1;
  height: 100%;
  background: #000;
}

<div class="CAContainer">
  <div class="CASideBorder" id="CALeftBorder"></div>
  <div class="CAMiddleContainer">
    <div class="CATopBorder"></div>
    <div class="CAMiddleTextContainer">
      text
    </div>
    <div class="CABottomBorderContainer">
      <div class="CABottomBorderLeft"></div>
      <div class="CABottomBorderRight"></div>
    </div>
  </div>
  <div class="CASideBorder" id="CARightBorder"></div>
</div>

还有 fiddle.

CASideBorder 不应该占据其父容器的 100%，其高度由 CAMiddleTextContainer 的文本大小和填充计算？我在这里错过了一些非常明显的东西吗？感谢任何帮助。

Answer 1

那是因为你有 align-items: center 的 flexbox，在这种情况下它将默认为内容高度。

你需要做的是删除它（让 align-items: stretch 发挥作用，因为它是默认值），同时从 CASideBorder.[=16= 中删除 height:100% ]

参见下面的演示：

.CAContainer {
  display: flex;
  flex-flow: row nowrap;
  justify-content: flex-start;
  margin: 0;
  padding: 0;
}

.CASideBorder {
  background: #000;
  width: 8px;
}

.CAMiddleContainer {
  display: flex;
  flex-flow: column nowrap;
  justify-content: center;
  align-items: center;
}

.CATopBorder {
  height: 8px;
  background: #000;
  width: 100%;
}

.CAMiddleTextContainer {
  padding: 40px 80px 40px 80px;
  font-size: 4em;
  color: #000;
}

.CABottomBorderContainer {
  display: flex;
  flex-flow: row nowrap;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  height: 8px;
}

.CABottomBorderLeft, .CABottomBorderRight {
  flex: 1;
  height: 100%;
  background: #000;
}

<div class="CAContainer">
  <div class="CASideBorder" id="CALeftBorder"></div>
  <div class="CAMiddleContainer">
    <div class="CATopBorder"></div>
    <div class="CAMiddleTextContainer">
      text
    </div>
    <div class="CABottomBorderContainer">
      <div class="CABottomBorderLeft"></div>
      <div class="CABottomBorderRight"></div>
    </div>
  </div>
  <div class="CASideBorder" id="CARightBorder"></div>
</div>

为什么我的 div 没有占据其父容器的 100% 高度？

Why is my div not taking up 100% height of its parent container?

html

css

vertical-alignment

flexbox