<div class="clearfix">
  <span class="float-left">左浮动</span>
  <span class="float-right">右浮动</span>
</div>

响应式浮动

<div class="float-sm-right">在大于小屏幕尺寸上右浮动</div>
<div class="float-md-right">在大于中等屏幕尺寸上右浮动</div>
<div class="float-lg-right">在大于大屏幕尺寸上右浮动</div>
<div class="float-xl-right">在大于超大屏幕尺寸上右浮动</div>
<div class="float-none">没有浮动</div>