10行原生JS实现文字无缝滚动

<section class="pro_quota_tip"> 
 <div class="tip_box"> 
  <a href="javascript:;" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >aaaaaaaaa</a> 
  <a href="javascript:;" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >bbbbbbbbbbbbbb</a> 
  <a href="javascript:;" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >ccccccccccc</a> 
  <a href="javascript:;" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >ddddddddddddddd</a> 
  <a href="javascript:;" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >aaaaaaaaaaaaaa</a> 
 </div> 
</section> 

body,#app{
  margin: 0;
  padding: 0;
  font-family:Helvetica;
  background: #f0efef !important;
  width: 100%;
  overflow-x: hidden;
}
a{
 text-decoration: none;
}
.pro_quota_tip{
  background: #fff;
  font-size: 14px;
  overflow: hidden;
  width: 200px;
  height: 49px;
  margin:0 auto;
  margin-top:10%
}
.pro_quota_tip .tip_box{
  position: relative;
}
.pro_quota_tip .tip_box a{
  color: red;
  display: block;
  width: 100%;
  padding:15px 5px;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

var tip_box_a_h = document.querySelectorAll('.tip_box a')[0].offsetHeight;
var i=0;
setInterval(()=>{
 let startScroll = setInterval(()=>{
  i++;
  document.querySelector('.tip_box').style.bottom = (tip_box_a_h/10)*i+'px';
  if(i%10==0)clearInterval(startScroll);
 },50)
 if(i>(10*(document.querySelectorAll('.tip_box a').length-2)))i = 0;
},2500)