Bootstrap 3 accordion chevron icons

Toggle accordion chevrons in Bootstrap 3

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.3/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.3/js/bootstrap.min.js"></script>
<section class="mbr-section extAccordion1" id="extAccordion1-1" style="background-color: rgb(255, 255, 255); padding-top: 100px; padding-bottom: 100px;">

    
        <div class="container">
            <div class="row">
                <div class="col-md-10 col-md-offset-1">
                    <div class="section-head text-center space30">
                        <h1>Accordion</h1>
                    </div>
                    <div class="clearfix"></div>
                    <div id="extAccordion1-1" class="panel-group accordionStyles" role="tablist" aria-multiselectable="true">
                        <div class="panel panel-default" style="display: block;">
                            <div class="panel-heading" role="tab" id="headingOne">
                                <span class="signSpan pseudoMinus"></span>
                                <h4 class="panel-title"><a role="button" class="" data-toggle="collapse" data-parent="#extAccordion1-1" data-core="" href="#collapseOneextAccordion1-1" aria-expanded="true" aria-controls="collapseOne"><span class="sign"></span>This is a accordion Title 1</a></h4>
                            </div>
                            <div id="collapseOneextAccordion1-1" class="panel-collapse noScroll collapse in" role="tabpanel" aria-labelledby="headingOne">
                                <div class="panel-body"><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur in nulla ut magna vehicula libero luctus in ipsum consequat faucibus. Ut porta nulla ac dapibus convallis. Curabitur sit amet massa quam. In ut ex auctor, porta neque quis, sagittis purus. Nunc auctor gravida magna, sed efficitur tortor tristique quis.</p></div>
                            </div>
                        </div>
                 ...