title: Bootstrap accordion header
body: <p>I have added an + - image to accordion header. When page loads, + sign looks bold. After clicking it looks normal. Is it because of header property> How to fix it ?</p>
  
  <pre><code>&lt;accordion-heading is-open="group.open"&gt;
                  &lt;div class="row" style="height:22px;"&gt;
                      &lt;div class="col-lg-2 col-md-2 col-sm-4 col-xs-8"&gt;
                          &lt;label class="aa-blue b h5"&gt;{{group.title}}&lt;/label&gt;
                      &lt;/div&gt;
                      &lt;div class="col-lg-2 col-md-2 col-sm-4 col-xs-8"&gt;
                          &lt;label class="aa-black b h5"&gt;{{group.stn}}&lt;/label&gt;
                          &lt;label class="aa-blue b h5"&gt;{{group.date}}&lt;/label&gt;
                      &lt;/div&gt;
                      &lt;div class="col-lg-7 col-md-7 col-sm-12 col-xs-12"&gt;
                          &lt;label class="h5"&gt;{{group.header|cut:true:60:' ...'}}&lt;/label&gt;
                      &lt;/div&gt;
                      &lt;div class="col-lg-1 col-md-1 col-sm-2 col-xs-4"&gt;
                          &lt;button class="btn btn-xs" ng-click="isCollapsed = !isCollapsed"&gt;
                              &lt;i ng-class="{'glyphicon glyphicon-plus': isCollapsed, 'glyphicon glyphicon-minus': !isCollapsed}"&gt;&lt;/i&gt;
                          &lt;/button&gt;
                      &lt;/div&gt;
                  &lt;/div&gt;
  &lt;/accordion-heading&gt;
  </code></pre>