html - 如何给 li before 属性添加样式

Question

这是时间线图表，我必须在每个 li 元素之前画一个圆圈。

ul.timeline>li:before {
  content: ' ';
  background: white;
  display: inline-block;
  position: absolute;
  border-radius: 50%;
  border: 3px solid #22c0e8;
  left: 20px;
  width: 20px;
  height: 20px;
  z-index: 400;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/>
<div class="container mt-5 mb-5">
  <div class="row">
    <div class="col-md-6 offset-md-3">
      <h4>Latest News</h4>
      <ul class="timeline">
        <li>
          <a target="_blank" href="https://www.totoprayogo.com/#">New Web Design</a>
          <a href="#" class="float-right">21 March, 2014</a>
          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque scelerisque diam non nisi semper, et elementum lorem ornare. Maecenas placerat facilisis mollis. Duis sagittis ligula in sodales vehicula....</p>
        </li>
        <li>
          <a href="#">21 000 Job Seekers</a>
          <a href="#" class="float-right">4 March, 2014</a>
          <p>Curabitur purus sem, malesuada eu luctus eget, suscipit sed turpis. Nam pellentesque felis vitae justo accumsan, sed semper nisi sollicitudin...</p>
        </li>
        <li>
          <a href="#">Awesome Employers</a>
          <a href="#" class="float-right">1 April, 2014</a>
          <p>Fusce ullamcorper ligula sit amet quam accumsan aliquet. Sed nulla odio, tincidunt vitae nunc vitae, mollis pharetra velit. Sed nec tempor nibh...</p>
        </li>
      </ul>
    </div>
  </div>
</div>

如何更改 HTML 元素的边框颜色？

这是完整的例子:https://bootsnipp.com/snippets/featured/simple-vertical-timeline

Answer 1

我想你想在两个蓝色圆圈之间添加边框，还想删除默认的 ul 样式。

我在您的代码中添加了一些 css 代码。在下面查看。

• 要删除默认的 ul 样式，我添加了 list-style-type 作为 无。
• 要添加连接列表项的垂直线，我 已将伪类元素 :before 添加到 ul.timeline。

ul.timeline {
    list-style-type: none;
}
ul.timeline:before {
    content: ' ';
    background: #d4d9df;
    display: inline-block;
    position: absolute;
    left: 29px;
    width: 2px;
    height: 100%;
    z-index: 400;
}
ul.timeline>li:before {
  content: ' ';
  background: white;
  display: inline-block;
  position: absolute;
  border-radius: 50%;
  border: 3px solid #22c0e8;
  left: 20px;
  width: 20px;
  height: 20px;
  z-index: 400;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/>
<div class="container mt-5 mb-5">
  <div class="row">
    <div class="col-md-6 offset-md-3">
      <h4>Latest News</h4>
      <ul class="timeline">
        <li>
          <a target="_blank" href="https://www.totoprayogo.com/#">New Web Design</a>
          <a href="#" class="float-right">21 March, 2014</a>
          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque scelerisque diam non nisi semper, et elementum lorem ornare. Maecenas placerat facilisis mollis. Duis sagittis ligula in sodales vehicula....</p>
        </li>
        <li>
          <a href="#">21 000 Job Seekers</a>
          <a href="#" class="float-right">4 March, 2014</a>
          <p>Curabitur purus sem, malesuada eu luctus eget, suscipit sed turpis. Nam pellentesque felis vitae justo accumsan, sed semper nisi sollicitudin...</p>
        </li>
        <li>
          <a href="#">Awesome Employers</a>
          <a href="#" class="float-right">1 April, 2014</a>
          <p>Fusce ullamcorper ligula sit amet quam accumsan aliquet. Sed nulla odio, tincidunt vitae nunc vitae, mollis pharetra velit. Sed nec tempor nibh...</p>
        </li>
      </ul>
    </div>
  </div>
</div>