z-index'ed 父 div 背景未显示答案

【问题标题】：z-index'ed parent div background not showingz-index'ed 父 div 背景未显示
【发布时间】：2017-06-06 00:01:12
【问题描述】：

我有一个带有视频背景的 bootstrap jumbotron。视频背景是绝对位置和 z-index: -1，而 jumbotron div 是相对位置和 z-index: 1。此处所需的结果是在视频顶部有一个白色透明覆盖。但是，即使我将其切换为纯色，背景属性也不可见。这是一支笔：https://codepen.io/anon/pen/LLEOoO?editors=1100

html

<div class="container">
  <div id="block-1" class="block row jumbotron">
    <div class="col col-md-12">
      <respond-html id="html-5" description="HTML">                  
        <video class="video-background" autoplay="" loop="" poster="/static/template/themes/video-theme/video/video.jpg">
          <source src="https://host.ohiocashflow.com/sites/home-giveaway/videos/Productive-Morning.webm" type="video/webm">
          <source src="https://host.ohiocashflow.com/sites/home-giveaway/videos/Productive-Morning.mp4" type="video/mp4">
        </video>
      </respond-html>
      <div id="image-1" class="respond-image">          
        <img src="https://host.ohiocashflow.com:443/sites/home-giveaway/files/logo.png">
      </div>
      <p>Your purpose in life has to be bigger and better than yourself...&nbsp;<a href="#">DONATE</a></p>
    </div>
  </div>
</div>

css

.container .jumbotron{
  position: relative;
  box-sizing: border-box;
  background: rgba(255,255,255,.5);
  border-radius: 0 !important;
  color: #fff;
  max-width: 100%;
  margin: 0 0 0 0;
  padding: 150px 0 0 0;
  text-align: center;
  height: 350px;
  z-index: 1;
}

.video-background { 
  position: absolute;
  top: 50%;
  left: 50%;
  min-width: 100%;
  min-height: 100%;
  width: 100%;
  height: auto;
  z-index: -1;
  -webkit-transform: translateX(-50%) translateY(-50%);
  transform: translateX(-50%) translateY(-50%);
}

【问题讨论】：

标签： css

【解决方案1】：

当您将z-index 添加到父级时，会创建一个从父级开始的新堆叠顺序。如果您希望子元素位于其父元素之下，请删除父元素 z-index 并在子元素上使用否定的 z-index。

.container .jumbotron{
  position: relative;
  box-sizing: border-box;
  background: rgba(255,255,255,.5);
  border-radius: 0 !important;
  color: #fff;
  max-width: 100%;
  margin: 0 0 0 0;
  padding: 150px 0 0 0;
  text-align: center;
  height: 350px;
}

.video-background { 
  position: absolute;
  top: 50%;
  left: 50%;
  min-width: 100%;
  min-height: 100%;
  width: 100%;
  height: auto;
  z-index: -1;
  -webkit-transform: translateX(-50%) translateY(-50%);
  transform: translateX(-50%) translateY(-50%);
}

<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet"/>
<div class="container">
  <div id="block-1" class="block row jumbotron">
    <div class="col col-md-12">
      <respond-html id="html-5" description="HTML">                  
        <video class="video-background" autoplay="" loop="" poster="/static/template/themes/video-theme/video/video.jpg">
          <source src="https://host.ohiocashflow.com/sites/home-giveaway/videos/Productive-Morning.webm" type="video/webm">
          <source src="https://host.ohiocashflow.com/sites/home-giveaway/videos/Productive-Morning.mp4" type="video/mp4">
        </video>
      </respond-html>
      <div id="image-1" class="respond-image">          
        <img src="https://host.ohiocashflow.com:443/sites/home-giveaway/files/logo.png">
      </div>
      <p>Your purpose in life has to be bigger and better than yourself...&nbsp;<a href="#">DONATE</a></p>
    </div>
  </div>
</div>

【讨论】：