Ruby on rails 使用bootstrap 3 css更改黑光面上的箭头图标方向

我试图添加箭头图标，当blacklight搜索面折叠并重新打开时，箭头图标会改变方向，如下所示：图标会出现，但折叠时不会改变。下面是每个刻面组或“面板默认”div的部分

---

它适用于我最新版本的Firefox，点击时图标会改变。

<div class="panel panel-default facet_limit blacklight-<%= facet_field.field.parameterize %> <%= 'facet_limit-active' if facet_field_in_params?(facet_field.field) %>">
  <div class="<%= "collapsed" if should_collapse_facet?(facet_field) %> collapse-toggle panel-heading" data-toggle="collapse" data-target="#<%= facet_field_id(facet_field) %>">
    <h5 class="panel-title">
        <a class="accordion-toggle" data-toggle="collapse"
        >
      <%= link_to facet_field_label(facet_field.field), "#", :"data-no-turbolink" => true %>
        </a>
    </h5>
  </div>
  <div id="<%= facet_field_id(facet_field) %>" class="panel-collapse facet-content <%= should_collapse_facet?(facet_field) ? 'collapse' : 'in' %>">
    <div class="panel-body">
       <%= yield %>
    </div>
   </div>
</div>

.panel-heading .accordion-toggle:after {
    /* symbol for "opening" panels */
    font-family: 'Glyphicons Halflings';  /* essential for enabling glyphicon */
    content: "\e114";    /* adjust as needed, taken from bootstrap.css */
    float: right;        /* adjust as needed */
    color: grey;         /* adjust as needed */
}
.panel-heading .accordion-toggle.collapsed:after {
    /* symbol for "collapsed" panels */
    content: "\e080";    /* adjust as needed, taken from bootstrap.css */
}