twitter bootstrap span未正确对齐

Question

由于某种原因，当我应用跨度时，跨度不会自己调整为正确的网格。它似乎并不重要，我应用跨度的元素是什么类型，在这种情况下，它是输入。我显然希望他们调整自己，我做错了什么？

小提琴这里：http://jsfiddle.net/fKQsj/

<div class="row-fluid"> 
       <div class="span12"> 
        <input type="text" class="span4" placeholder="First" /> 
        <input type="text" class="span4" placeholder="Middle" /> 
        <input type="text" class="span4" placeholder="Last" /> 
       </div> 
      </div> 
      <div class="row-fluid"> 
       <div class="span12"> 
        <input type="text" class="span4" placeholder="City" /> 
        <input type="text" class="span2" placeholder="State" /> 
        <input type="text" class="span2" placeholder="Zip5" /> 
        <input type="text" class="span4" placeholder="Store" /> 
       </div> 
      </div> 
      <div class="row-fluid"> 
       <div class="span12"> 
        <div class="span4 offset8"> 
         <button class="btn btn-success pull-right">Search</button> 
        </div> 
       </div> 
      </div> 

Answer 1

从手动

For multiple grid inputs per line, use the .controls-row modifier class for proper spacing. 
It floats the inputs to collapse white-space, sets the proper margins, and clears the float. 

采取