Grid - Nested

To nest your content with the default grid, add a new .row and set of .col-* columns within an existing .col-* column. Nested rows should include a set of columns that add up to the number of columns of its parent.

.col-md-12
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1 
<div class="row">
    <div class="col-md-12">
      .col-md-12
      <div class="row">
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
        <div class="col-md-1">
          .col-md-1
        </div>
        
      </div>
    </div>
  </div>