/*定义canvas样式*/
#canvas{ display:block;
         margin:0 auto;
		 }
		 
#coltroller{ width:600px;
             margin:0 auto;
			 }
			 
.op_btn{ float:right;
		 margin:10px 0 0 10px;
		 border:2px solid #aaa;
		 width:80px;
		 height:40px;
		 line-height:40px;
		 font-size:20px;
		 text-align:center;
		 border-radius:5px 5px;
		 cursor:pointer;
		 background-color:white;
		 font
		 }
		  
.op_btn:hover{
	background-color:#def;
	}
.clearfix{
	clear:both;
	}