html - Font Awesome 垂直图标对齐

Question

为什么 vertical-align: middle; 没有将图标对齐到标题的中间？

    .custom {
        color: white;
        vertical-align: middle;
    }
    .header {
        width: 100%;
        height: 40px;
        background: rgb(40,40,40);
    }

<link href="http://netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css" rel="stylesheet"/>
<div class="header">
    <i class="fa fa-facebook custom" aria-hidden="true"></i>
    <i class="fa fa-twitter custom" aria-hidden="true"></i>
    <i class="fa fa-instagram custom" aria-hidden="true"></i>
    <i class="fa fa-google-plus custom" aria-hidden="true"></i>
</div>

Answer 1

如今，垂直居中对齐的最佳方式是使用 flexbox。另见:

https://css-tricks.com/snippets/css/a-guide-to-flexbox/

https://philipwalton.github.io/solved-by-flexbox/demos/vertical-centering/

.custom {
        color: white;
        vertical-align: middle;
    }

.header {
  
  display:flex;
  align-items: center;

        width: 100%;
        height: 40px;
        background: rgb(40,40,40);
    }

<link href="http://netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css" rel="stylesheet"/>
<div class="header">
    <i class="fa fa-facebook custom" aria-hidden="true"></i>
    <i class="fa fa-twitter custom" aria-hidden="true"></i>
    <i class="fa fa-instagram custom" aria-hidden="true"></i>
    <i class="fa fa-google-plus custom" aria-hidden="true"></i>
</div>