I'm using Twitter Bootstrap 3, and I have problems when I want to align vertically two div, for example — JSFiddle link:
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap-theme.min.css">
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<div class="row">
<div class="col-xs-5">
<div style="height:5em;border:1px solid #000">Big</div>
</div>
<div class="col-xs-5">
<div style="height:3em;border:1px solid #F00">Small</div>
</div>
</div>
The grid system in Bootstrap uses float: left, not display:inline-block, so the property vertical-align doesn't work. I tried using margin-top to fix it, but I think this is not a good solution for the responsive design.