一个是包裹全部的div，一个是包裹表单的div、一个是logo的div标签，一共三个

<div class="bg-div">

  <div class="search-box">

  <div class="logo"></div>

<form class="search-form" action="https://cn.bing.com/search" target="_blank" id="search-form">

<input type="text" class="search-text" name="q" id="search_input" autocomplete="off"/>

<input type="submit" class="search-button" value=""/>

</form>

  </div>

 </div>

 <div class="suggest" id="search-suggest" style="display:none">

<ul id="search-result">

<li> 搜索内容 </li>

<li> 搜索内容 </li>

</ul>

</div>