*{ margin:0; padding:0;}
.bigdiv{ width:100px; height:100px; top:50%; left:50%; margin-top:-50px; margin-left:-50px;position:absolute;}
.yuan{ width:80px; height:80px; background:#666; position:absolute; margin:auto; left:0; top:0; right:0; bottom:0}
.yuan:hover{animation:hehe 3s ease infinite;-webkit-animation:hehe 3s ease infinite;}
@keyframes hehe
{
0%   {margin-top:0px; margin-left:0}
50%  {margin-top:10px; margin-left:10px}
100% {margin-top:0px; margin-left:0}
}
@-webkit-keyframes hehe
{
0%   {rotate(0deg); }

100% {rotate(360deg);
 }
}