/* ------------------------------------------
 * IT书包
 * 网址：www.itshubao.com
 * 整理：yinq<3331653644@qq.com> 
 -------------------------------------------- */
* {
	margin: 0;
	padding: 0;
}
#canvas {
	display: block;
	margin: 10px auto;
	border: 1px solid #bbb;
	outline: none;
}
.box {
	position: relative;
}