z-index不适用于:: after / :: before元素之后？

Question

z-index不适用于其::before / ::after元素。我在这里分享以下代码。

.or {
  border: 2px solid #8fc300;
  border-radius: 5px;
  color: #333;
  font-size: 17px;
  font-weight: 600;
  height: 34px;
  line-height: 26px;
  text-align: center;
  width: 34px;
  margin-top: 64px;
  margin-left: 20px;
  margin-right: 20px;
  background: #fff;
  /*For z-index - keep the green area on top*/
  position: relative;
  z-index: 11;
}
.or::after {
  background: red;
  content: "";
  display: block;
  height: 116px;
  margin-left: 15px;
  margin-top: -68px;
  width: 4px;
  /*For z-index - keep the green area on top*/
  position: relative;
  z-index: 9;
}

<div class="or"></div>

Answer 1

您可以从父元素中删除z-index，并在伪元素上使用否定z-index: -1。如果您只想要红线上的绿线，则需要从父级DEMO

中删除白色背景

＆＃13;

＆＃13;

.or {
  border: 2px solid #8fc300;
  border-radius: 5px;
  color: #333;
  font-size: 17px;
  font-weight: 600;
  height: 34px;
  line-height: 26px;
  text-align: center;
  width: 34px;
  margin-top: 64px;
  margin-left: 20px;
  margin-right: 20px;
  background: #fff;
  /*For z-index - keep the green area on top*/
  position: relative;
}
.or::after {
  background: red;
  content: "";
  display: block;
  height: 116px;
  margin-left: 15px;
  margin-top: -68px;
  width: 4px;
  /*For z-index - keep the green area on top*/
  position: absolute;
  z-index: -1;
}

＆＃13;

<div class="or"></div>

＆＃13;

＆＃13;

＆＃13;

Answer 2

伪元素被视为其相关元素的后代。因此，.or::after将从z-index: 11继承.or。

只需从z-index移除.or并在z-index: -1上更新.or::after

＆＃13;

＆＃13;

.or {
  border: 2px solid #8fc300;
  border-radius: 5px;
  color: #333;
  font-size: 17px;
  font-weight: 600;
  height: 34px;
  line-height: 26px;
  text-align: center;
  width: 34px;
  margin-top: 64px;
  margin-left: 20px;
  margin-right: 20px;
  background: #fff;
  /*For z-index - keep the green area on top*/
  position: relative;
}
.or::after {
  background: red;
  content: "";
  display: block;
  height: 116px;
  margin-left: 15px;
  margin-top: -68px;
  width: 4px;
  /*For z-index - keep the green area on top*/
  position: relative;
  z-index: -1;
}

＆＃13;

<div class="or"></div>

＆＃13;

＆＃13;

＆＃13;

Answer 3

这是一个可能的解决方案。

在.or元素上，不要设置z-index值并删除白色背景（但这可能不是你需要的）。

在:after伪元素上，设置z-index: -1，这将导致它在父元素下呈现（绘制）。

.or {
  border: 6px solid #8fc300;
  border-radius: 5px;
  color: #333;
  font-size: 17px;
  font-weight: 600;
  height: 34px;
  line-height: 26px;
  text-align: center;
  width: 34px;
  margin-top: 64px;
  margin-left: 20px;
  margin-right: 20px;
  /*background: #fff;*/
  /*For z-index - keep the green area on top*/
  position: relative;
  /*z-index: 11;*/
}
.or::after {
  background: red;
  content: "";
  display: block;
  height: 116px;
  margin-left: 15px;
  margin-top: -68px;
  width: 4px;
  /*For z-index - keep the green area on top*/
  position: relative;
  z-index: -1;
}

<div class="or"></div>

Answer 4

如果您想要这样的话，试试这个。我确实更改了.or类的样式，例如background-color: transparent删除了位置，z-index和.or::after z-index: -11

＆＃13;

＆＃13;

.or {
  border: 2px solid #8fc300;
  border-radius: 5px;
  color: #333;
  font-size: 17px;
  font-weight: 600;
  height: 34px;
  line-height: 26px;
  text-align: center;
  width: 34px;
  margin-top: 64px;
  margin-left: 20px;
  margin-right: 20px;
  background: transparent;
  /*For z-index - keep the green area on top*/
  /*position: relative;*/
  /*z-index: 11;*/
}
.or::after {
  background: red;
  content: "";
  display: block;
  height: 116px;
  margin-left: 15px;
  margin-top: -68px;
  width: 4px;
  /*For z-index - keep the green area on top*/
  position: relative;
  z-index: -11;
}

＆＃13;

<div class="or"></div>

＆＃13;

＆＃13;

＆＃13;