This code only scales horizontally:
   <div class="row">
       <div class="box col-xs-3"></div>
       <div class="box col-xs-3"></div>
       <div class="box col-xs-3"></div>
       <div class="box col-xs-3"></div>
    </div>
The height should also be scalable, someone knows how to do this with bootstrap?
The width and height are the same here:

After resizing window the width and height are not the same anymore:
