bootstrap栅格例子

<div class="container-fluid ">
<div class="row">
<div class="col-md-3">.col-md-3
<div class="row">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4">.col-md-4</div>
</div>
</div>
<div class="col-md-9">.col-md-9</div>
</div>

<div class="row">
<div class="col-md-3">.col-md-3</div>
<div class="col-md-6">.col-md-6</div>
<div class="col-md-3">.col-md-3</div>
</div>
</div>