html - Z-index 不适用于带有剪辑路径的伪元素

Question

我正在尝试使用伪元素为我的剪辑路径创建一个边框。我已经尝试改变它们的位置，而我的伪元素仍然在它上面。我怎样才能改变这个？你可以在这里看到我的代码。

#shield {
  z-index: 1;
  background-color: red;
  box-shadow: 1px 1px 1px black;
  background-image: url("https://upload.wikimedia.org/wikipedia/commons/9/91/Bras%C3%A3o_Porto_Feliz.png");
  background-size: 50%;
  background-repeat: no-repeat;
  background-position: center;
  background-blend-mode: multiply;
  display: inline-block;
  height: 120px;
  width: 200px;
-webkit-clip-path: polygon(100% 0, 100% 75%, 50% 100%, 0% 75%, 0 0);
clip-path: polygon(100% 0, 100% 75%, 50% 100%, 0% 75%, 0 0);
}

#logo {
  width: 100px;
  height: 100px;
}
#shield::before {
  top: 0;
  left: 0;
  transform: scale(1.2);
  content:"";
  display: block;

  width: 100%;
  height: 100%;
  background-color: black;
  position: absolute;
  z-index: -1; 
  
}

		      <div class="navbar-brand navbar-brand-centered" id="shield">
          </div>

要查看我想要的内容，只需删除::before 元素

完整示例在 here 中

提前致谢:)

Answer 1

只需翻转一下即可。在::after 中使用背景图片，在实际的 div 中使用黑色。

#shield {
  z-index: 1;
  background-color: black;
  box-shadow: 1px 1px 1px black;
  position: relative;
  
  
  display: inline-block;
  height: 120px;
  width: 200px;
-webkit-clip-path: polygon(100% 0, 100% 75%, 50% 100%, 0% 75%, 0 0);
clip-path: polygon(100% 0, 100% 75%, 50% 100%, 0% 75%, 0 0);
}

#logo {
  width: 100px;
  height: 100px;
}
#shield::before {
  top: 0;
  left: 0;
  transform: scale(1.2);
  content:"";
  display: block;

  width: 100%;
  height: 100%;
  background-image: url("https://upload.wikimedia.org/wikipedia/commons/9/91/Bras%C3%A3o_Porto_Feliz.png");
  background-repeat: no-repeat;
  background-position: center;
  background-blend-mode: multiply;
  
  position: absolute;
  z-index: 1; 
  background-size: 50%;
}

<div id="shield"></div>