代码编辑器：
x
1
2
<meta charset="utf-8" />3
<link rel="stylesheet" href="https://cdn.bootcss.com/font-awesome/4.7.0/css/font-awesome.css">4
<div>5
<span class="fa-stack fa-lg">6
<i class="fa fa-circle-thin fa-stack-2x"></i>7
<i class="fa fa-twitter fa-stack-1x"></i>8
</span>9
fa-twitter on fa-circle-thin<br>10
11
<span class="fa-stack fa-lg">12
<i class="fa fa-circle fa-stack-2x"></i>13
<i class="fa fa-twitter fa-stack-1x fa-inverse"></i>14
</span>15
fa-twitter (inverse) on fa-circle<br>16
17
<span class="fa-stack fa-lg">18
<i class="fa fa-camera fa-stack-1x"></i>