text center of glyphicon

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
 <div class="container">
    <i class="glyphicon glyphicon-resize-horizontal icon-size"></i>
    <span id="trx">TRX</span>
    <span id="ack">ACK</span>
</div>

CSS

.icon-size {
    font-size:60px;
}

#trx{
   /* background: red;*/
    position:absolute;
    left:32px; /** you can make changes here to change position **/
    top:7px;
    font-size:14px;
    z-index: 3;
}
#ack{
   /* background: red;*/
    position:absolute;
    left:32px; /** you can make changes here to change position **/
    top:37px;
    font-size:14px;
    z-index: 3;
}