滚动平滑滚动（已解决）

Question

我对此代码（https://codepen.io/MAJO-SEARCH/pen/gOOyWWb）有疑问。问题在于，第一次加载页面时，页面的页脚会被剪切掉，更改页面的宽度后，一切都会恢复正常。我不知道是怎么引起的。负责该脚本的脚本位于底部：

var lastPosition = 0;
var html = document.documentElement;
var body = document.body;
html.style.height = body.offsetHeight + 'px';
resizeHandler = function(){
  html.style.height = body.offsetHeight + 'px';
}
window.addEventListener('resize',resizeHandler,false);
clickHandler = function(){
wrapper.style.height = smooth.offsetHeight + 'px';
window.scrollTo(0,offsetTop);
smooth.style.transform = 'translate3d(0px, -' + toggle.offsetTop + 'px, 0px)';
lastPosition = window.pageYOffset;
return false;
}

var scroll = window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    function(callback) {
        window.setTimeout(callback, 1000 / 60)
    };
function loop() {
    if (lastPosition == window.pageYOffset) {
        scroll(loop);
        return false;
    } else lastPosition = window.pageYOffset;
    body.style.transform = 'translate3d(0px, -' + lastPosition + 'px, 0px)';
    scroll(loop);
  return true;
}
body.addEventListener('scroll',loop,true);
loop();