动态计算rem

在根文件中添加

<script>
      (function(w,d) {
        function setSize() {
          var screenWidth = d.documentElement.clientWidth;
          var currentFontSize = screenWidth * 100 / 750;
          d.documentElement.style.fontSize = currentFontSize + 'px';
        }
        w.addEventListener('resize',setSize);
        w.addEventListener('pageShow',setSize)
        w.addEventListener('DOMContentLoaded',setSize)
      })(window,document)
    </script>