如何将两个图像与Bootstrap 3并排居中？

Question

I can't seem to get the two images of class 'social' side-by-side, central to the column of class 'col-sm-4'. Instead they stack as the screen size decreases. Any ideas how I can do this responsively?

HTML

<div class="container-fluid">
     <div class="row" style="border-top: 0">
          <!-- Profile info -->
          <div class="col-sm-4 col-sm-offset-4">
               <img class="img-circle img-responsive" src="images/callum.jpg">
               <h1 class="text-center" style="color: #3FA2B2">Callum Messiter</h1>
               <p class="text-center">100-trillion cells and 100-billion neurons defying the 1 in 10<sup>2,685,000</sup> chance of me existing.</p> 
               <img class="social" src="images/twitter.png">
               <img class="social" src="images/github.png">
          </div>
     </div>
</div>

CSS

.row{
   border-top: 1px solid #808080;
   padding-left: 10px;
   padding-right: 10px;
   padding-bottom: 10px;
}

.col-sm-4{
   height: 450px;
}

.img-circle{
   height: 200px;
   width: 200px;
   margin: 0 auto;
   position: relative;
   top: 40px;
   border: 2px solid white;
}

.text-center{
   font-family: helvetica;
   color: white;
   position: relative;
   top: 50px;
}

span{
   font-weight: bold;   
   background-color: #e6e6e6;
   color: #3FA2B2;
   padding: 3px 7px 3px 7px;
}

.social{
   height: 50px;
   width: 50px;
   margin: 0 auto;
}

Answer 1

Add class text-center before img. like this

<div class="text-center">
  <img class="social" src="https://files.allaboutbirds.net/wp-content/themes/html5blank-stable/images/blue-winged-warbler.jpg">
  <img class="social" src="https://files.allaboutbirds.net/wp-content/themes/html5blank-stable/images/blue-winged-warbler.jpg">
</div>

DEMO HERE https://jsfiddle.net/ff9g43t8/

Answer 2

Try:

.social {
 display: inline-block;
}