::after 不会堆叠在元素下方

Question

我需要灰色垂直线位于 "latest work" 作品下方。当我将 z-index 设置为负数时，虽然它消失了，但我假设在 body 下？希望这是一个简单的解决方案。我附上了我的模型图像以显示它应该是什么样子。我有一个背景为 #212121 的 div，所以副本 "latest work" 上下都有填充，看起来像是线在下面。

body {
 font-size: 16px;
 background: #f9f9f9;
}
.container {
 max-width: 1600px;
}

#dt-lpStatic {
 height:60px;
 width: 100%;
 padding:6px 0;
 font-family: 'Montserrat', sans-serif;
 font-size: 0.875em;
 text-transform: uppercase;
}
#dt-lpStatic ul {
 float: left;
 margin-top: 3px;
}
#dt-lpStatic ul li {
 display: inline;
 color:#545454;
 margin-left:40px;
}
#dt-lpStatic ul li:nth-child(1) {
 margin-left:0;
}
.subscribe-btn-muted {
 padding:12px 50px;
 border:2px solid #555;
 border-radius: 13%/50%;
  -webkit-border-radius: 13%/50%;
  -moz-border-radius: 13%/50%;
 float:right;
 color:#555;
}
#hero {
 width:100%;
 background: #212121;
 height:100vh;
}
#hero-content {
 margin:30vh auto;
 text-align: center;
}
#hero .secTitle-bg-dark {
 width:200px;
 padding: 15px 0;
 font-family: 'Open Sans', sans-serif;
 font-style: italic;
 color: #555;
 font-size: 1.5em;
 font-weight: 300;
 margin:30vh auto;
 background: #212121;
}
.secTitle-bg-dark:after {
    content:"";
    position: absolute;
    z-index: 0;
    top: 65vh;
    bottom: 0;
    left: 50%;
    border-left: 2px solid #313131;
}

<body>
 <section id="hero">
  <header id="dt-lpStatic">
   <div class="container">
    <ul>
     <li><img src="imgs/logo-muted.png" alt="RH logo"></li>
     <li>Home</li>
     <li>Blog</li>
     <li>About</li>
     <li>Get In Touch</li>
    </ul>
    <div class="subscribe-btn-muted">Subscribe</div>
   </div>
  </header>
  <div id="hero-content">
   <img src="imgs/logo-full-big.png" alt="RH Visual Design logo">
   <div class="secTitle-bg-dark">latest work</div>
  </div>
 </section>
</body>

Answer 1

将 display: block; 添加到 :after 元素 - 伪元素需要它来进行块布局。

Answer 2

这实际上是 flexbox 的一个非常好的候选者。只需这样做，您就可以大大简化代码：

编辑：友情提示：伪元素应该以 :: 为前缀，例如 ::before 和 ::after。伪选择器只有一个冒号，如 a:hover 和 input:focus.

body {
  background-color: #333;
}

.latest-work {
  color: #999;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.latest-work span {
  display: block;
  padding: 10px 0;
}

.latest-work::before,
.latest-work::after {
  width: 1px;
  height: 100px;
  content: '';
  background-color: #999;
}

<div class="latest-work">
    <span>latest work</span>
</div>

::after 不会堆叠在元素下方

::after won't stack below element

html

css

z-index