为什么我的按钮与窗体和字符串不在同一行？

Question

我无法找到方式将按钮放在与响应式设计中的窗体和文本相同的行上。

<div class="col-xs-12 col-md-6 nopadding"> 
       <div class="row col-xs-8 col-md-8 pts-vcenter"> 
        <div class="col-xs-4 col-sm-5 col-md-5"> 
         <span class="bold">{l s='Voucher' mod='onepagecheckoutps'}</span> 
        </div> 
        <div class="col-xs-4 col-sm-7 col-md-7 nopadding-xs"> 
         <input type="text" class="discount_name form-control" id="discount_name" name="discount_name" value="{if isset($discount_name) && $discount_name}{$discount_name|escape:'htmlall':'UTF-8'}{/if}" /> 
        </div> 
       </div> 
       <div class="col-xs-4"> 
        <span type="button" id="submitAddDiscount" name="submitAddDiscount" class="btn btn-default btn-small"> 
         {l s='Add' mod='onepagecheckoutps'} 
        </span> 
       </div> 
      </div> 

Answer 1

尝试使用col-xs-12这样的：

<div class="col-xs-12"> 
    <span type="button" id="submitAddDiscount" name="submitAddDiscount" class="btn btn-default btn-small"> 
    {l s='Add' mod='onepagecheckoutps'} 
    </span> 
</div> 

而且不要忘了使用的行类:)