鼠标悬停出现页面

  <div class="downBottom">
　　　　<a target="_blank" href="javascript:void(0);" >Download</a>
       <div  class="QRcode_img"><img src="./QRcode.png" width="160"></div>
  </div>

.downBottom:hover .QRcode_img{
   display: block;
 }

.downBottom .QRcode_img{
   display: none;
   position: absolute;
   margin-top: 15px;
   border: 1px solid #fafafa;
   padding: 10px;
   background: white;
   border-radius: 10px;
   margin-left: 10px;
   height: 160px;
   width: 160px;
 }