rem使用記錄

<script>
    window.onload = function(){
      getRem(720,100)
    };
    window.onresize = function(){
      getRem(720,100)
    };
    function getRem(pwidth,prem){
      var html = document.getElementsByTagName("html")[0];
      var oWidth = document.body.clientWidth || document.documentElement.clientWidth;
      html.style.fontSize = oWidth/pwidth*prem + "px";
    }
    //小米官網的寫法
    !function(n){
      var e=n.document,
          t=e.documentElement,
          i=720,
          d=i/100,
          o="orientationchange"in n?"orientationchange":"resize",
          a=function(){
              var n=t.clientWidth||320;n>720&&(n=720);
              t.style.fontSize=n/d+"px"
          };
          e.addEventListener&&(n.addEventListener(o,a,!1),e.addEventListener("DOMContentLoaded",a,!1))
    }(window);
</script>