为什么bootstrap的轮播图的指标位置在移动设备上看是偏的呢？

Question

 <div class="banner" id="home">

   <div class="slider" >
<div class="callbacks_container">
  <ul class="rslides" id="slider">
    <li>
      <img src="images/banner1.jpg" alt="">
      
      
    </li>
    <li>
      <img src="images/banner2.jpg" alt=""> 
                  
    </li>
    <li>
      <img src="images/banner3.jpg" alt="">
        
    </li>
  </ul>
    </div>
  </div>
 </div>