css3 javascript 实现菜单按钮特效

一个菜单按钮特效案例，简单的实现了动态效果。

代码效果预览地址：

http://code.w3ctech.com/detail/2504

<div class="bar" id="menubar">

  <div class="menu" id="menu0">

  </div>
  <div class="menu" id="menu1">

  </div>
  <div class="menu" id="menu2">

  </div>
</div>

 .bar{
             width:40px;
             height:40px;
             border:1px solid #ccc;
             border-radius:50%;
             position:fixed;
             top:10px;
             right:25px;
             z-index:;
             cursor:pointer;
         }
         .menu{
             width:20px;
             height:2px;
             background-color:#ccc;
             position:absolute;
             transform:translate3d(-50%,-50%,0);
             left:50%;
             transition:all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) 0s
         }
         #menu0{
             top:30%;
         }
         #menu1{
             top:50%;
         }
         #menu2{
             top:70%;
         }

 window.onload = function () {
             var menubar = document.getElementById("menubar");
             var menu0 = document.getElementById("menu0");
             var menu1 = document.getElementById("menu1");
             var menu2 = document.getElementById("menu2");
             var i = 0;
             menubar.onclick = function () {
                 i++;
                 if (i % 2 == 1) {
                     menu0.style.top = 50 + "%";
                     menu1.style.display = "none";
                     menu2.style.top = 50 + "%";
                     menu0.style.transform = "translate3d(-50%,-50%,0) rotate(135deg)";
                     menu2.style.transform = "translate3d(-50%,-50%,0) rotate(405deg)";
                 }
                 else {
                     menu0.style.transform = "translate3d(-50%,-50%,0) rotate(0deg)";
                     menu2.style.transform = "translate3d(-50%,-50%,0) rotate(0deg)";
                     menu0.style.top = 30 + "%";
                     menu2.style.top = 70 + "%";
                     menu1.style.display = "block";
                 }
             }

         }