/*四角*/
.box {
	position: relative;
}
.box::before{
	content: '';
	position: absolute;
	width: 22px;
	height: 22px;
	background-image: url(../shuju-img/lt.png);
	background-repeat: no-repeat;
	background-size: 100% 100%;
}
.box::after{
	content: '';
	position: absolute;
	right: 0;
	top: 0;
	width: 22px;
	height: 22px;
	background-image: url(../shuju-img/rt.png);
	background-repeat: no-repeat;
	background-size: 100% 100%;
}
.box-item {
	position: relative;
}
.box-item::before{
	content: '';
	position: absolute;
	left: 0px;
	bottom: 0px;
	width: 22px;
	height: 22px;
	background-image: url(../shuju-img/lb.png);
	background-repeat: no-repeat;
	background-size: 100% 100%;
}
.box-item::after{
	content: '';
	position: absolute;
	right: 0px;
	bottom: 0px;
	width: 22px;
	height: 22px;
	background-image: url(../shuju-img/rb.png);
	background-repeat: no-repeat;
	background-size: 100% 100%;
}