JavaScript与CSS3结合实现动态时钟效果

<body>
    <ul id='box'></ul>
</body>

<style>
      *{
        margin: 0;
        padding: 0;
      }
      body{
        background-color: #aaa;
      }
      ul{
        width: 400px;
        height: 400px;
        border: 5px solid skyblue;
        margin: 100px auto 0 auto;
        border-radius: 50%;
         background: radial-gradient(green 50%, yellow 100%);;
        position: relative;

      }
      ul li{
        width: 2px;
        height: 15px;
        list-style: none;
        background-color: #fff;
        position: absolute;
        left: 199px;
        transform-origin: center 200px;
      }

      h1{
        width: 2px;
        height: 180px;
        background-color: orange;
        position: absolute;
        left: 199px;
        top:20px;
        -transition: 1s linear;
        transform-origin: center 180px;
      }
      h2{
        width: 6px;
        height: 160px;
        background-color: #fff;
        position: absolute;
        left: 197px;
        top:40px;
        transform-origin: center 160px;
        border-radius:20%;
      }

      h3{
        width: 8px;
        height: 140px;
        background-color: #fff;
        position: absolute;
        left: 196px;
        top:60px;
        transform-origin: center 140px;
        transform: rotate(0deg);
        border-radius: 20%;
      }
      h4{
        width: 30px;
        height: 30px;
        position: absolute;
        left: 185px;
        top:185px;
        border-radius: 50%;
        background-color: orange;
      }

      span{
        display: inline-block;
        width: 20px;
        height: 20px;
        line-height: 20px;
        text-align: center;
        font-size: 24px;
        position: absolute;
        left: -10px;
        top: 28px;
        color: #fff;
      }

</style>

(function(){
      var oUl=document.getElementById('box');
      var timer=null;
      for(var i=0,j=0;i<60;i++,j+=6){
        var oLi=document.createElement('li');
        oLi.style.transform='rotate('+j+'deg)';
        if(i%5==0){
          oLi.style.height='20px';
          var oSpan=document.createElement('span');
          oSpan.style.transform='rotate('+(-j)+'deg)';
          if(i==0){
            oSpan.innerHTML='12';
            oSpan.style.fontSize='30px';
            oSpan.style.left='-17px';
          }else{
            oSpan.innerHTML=parseInt(i/5);
            if(i%15==0){
              oSpan.style.fontSize='36px';
            }
          }
          oLi.appendChild(oSpan);
        }
        if(i==0){
          var oH1=document.createElement('h1');
          var oH2=document.createElement('h2');
          var oH3=document.createElement('h3');
          var oH4=document.createElement('h4');
          oUl.appendChild(oH1);
          oUl.appendChild(oH2);
          oUl.appendChild(oH3);
          oUl.appendChild(oH4);
        }
        oUl.appendChild(oLi);
      }
      var oH=document.getElementsByTagName('h3')[0];
      var oM=document.getElementsByTagName('h2')[0];
      var oS=document.getElementsByTagName('h1')[0];
      timer=setInterval(function(){
         var now = new Date();
         var s=now.getSeconds();
         var m=now.getMinutes()+s/60;
         var h=now.getHours()+m/60;
         oS.style.transform='rotate('+s*6+'deg)';
         oM.style.transform='rotate('+m*6+'deg)';
         oH.style.transform='rotate('+(h%12)*30+'deg)';
      },30);

    })();