https://niubaotiyuzhcn.com.cn/skin/bootstrap/js/main.js

1document.addEventListener('DOMContentLoaded',function(){
2  var b=document.querySelector('.menu-toggle'),n=document.querySelector('#siteNav');
3  if(b&&n){
4    b.addEventListener('click',function(){
5      var o=n.classList.toggle('open');
6      b.setAttribute('aria-expanded',o?'true':'false')
7    }
8    )
9  }
10  var t=document.querySelector('.back-to-top');
11  if(t){
12    window.addEventListener('scroll',function(){
13      window.scrollY>400?t.classList.add('show'):t.classList.remove('show')
14    }
15    );
16    t.addEventListener('click',function(){
17      window.scrollTo({
18        top:0,behavior:'smooth'
19      }
20      )
21    }
22    )
23  }
24}
25);