边框像素问题为什么解决不了

代码哪里有问题吗?

(function($) {
                'use strict'
                var docEl = document.documentElement;

            // 解决dpr一边框像素问题
            var dpr = window.devicePixelRatio || 1,
                viewPortEl = document.querySelector('meta[name="viewport"]'),
                maxWidth = 540,
                minWidth = 320;

            dpr = dpr >= 3 ? 3:(dpr >= 2 ? 2 :1);

            docEl.setAttribute('data-dpr',dpr);
            docEl.setAttribute('max-width', maxWidth);
            docEl.setAttribute('min-width', minWidth);

            var scale = 1/ dpr,
            content = 'width=device-width, initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' +scale+',user-scalable=no';  

            if(viewPortEl){
                viewPortEl.setAttribute('content',content);
            }else{
                viewPortEl = createElement('meta');
                viewPortEl.setAttribute('name','viewport');
                viewPortEl.setAttribute('content',content);
                document.head.appendChild(viewPortEl);
            }

            // 设置Rem的单位
            function setRemUnit(){
                // 获取rem基准值
                var viewWidth = docEl.clientWidth;
                
                if(viewWidth && (viewWidth / dpr > maxWidth)) {
                    viewWidth = maxWidth * dpr;
                }else if(viewWidth && (viewWidth / dpr < minWidth)){
                    viewWidth = minWidth * dpr;
                }

                var rem =viewWidth / 10;

                docEl.style.fontSize= rem + 'px';
            }
            setRemUnit();

            // 页面发生变化执行setRemUnit方法计算html根元素的font-size
            window.addEventListener('resize',setRemUnit);
            window.addEventListener('pageshow',setRemUnit);
            })(jQuery);