twitter bootstrap 3列堆积

Question

我有我的标记设置显示3列twitter引导布局，而是divs堆叠。这应该是真正简单的，我不知道为什么列不是列。

<div class="container-fluid"> 
     <div class="row"> 
     <div class="header"> 

      <div class=".col-xs-6 .col-sm-4"> 

       <a href="{{ URL::route('home') }}"> 

       <div class="header_group"> 
       <img src="../../images/me.png"> 
       <span><h1 class="header_text">Logo</h1></span> 
       </div><!--header group --> 
       </a> 

      </div> 

      <div class=".col-xs-6 .col-sm-4"> 
      middle 
      </div> 

      <div class=".col-xs-6 .col-sm-4"> 
      @include('layout.navigation') 
      </div> 


     </div><!-- main header --> 
     </div><!-- row --> 
     </div><!-- container --> 

Answer 1

类名

<div class="container"> 
     <div class="row"> 
      <div class="header">  

      <div class="col-xs-6 col-sm-4">  
       Column1  
      </div> 

      <div class="col-xs-6 col-sm-4"> 
       Column 2 
      </div> 

      <div class="col-xs-6 col-sm-4"> 
       Column3 
      </div> 

      </div><!-- header --> 

     </div><!-- row --> 
</div><!-- container --> 

Here is the jsfiddle link