怎么给倒计时进行美化？

Question

<div class="logo">  <a href="#" class="a"><img src="images/logo.jpg" alt=""></a>  <div class="time">距离下次更新还剩:<br><span id="LeftTime"></span></div><script>function FreshTime(){        var endtime=new Date("2017/11/28,12:20:12");//结束时间        var nowtime = new Date();//当前时间        var lefttime=parseInt((endtime.getTime()-nowtime.getTime())/1000);         d=parseInt(lefttime/3600/24);        h=parseInt((lefttime/3600)%24);        m=parseInt((lefttime/60)%60);        s=parseInt(lefttime%60);               document.getElementById("LeftTime").innerHTML=d+" 天 "+h+" 时 "+m+" 分 "+s+" 秒";        if(lefttime<=0){        document.getElementById("LeftTime").innerHTML="更新完成";        clearInterval(sh);        }}FreshTime()var sh;sh=setInterval(FreshTime,1000);</script></div>