.lesson article {
    background: #3bb84f;
}
.lesson {
    background: url(../images/bg2-5.png) no-repeat bottom center;
}

.junior_banner{
	display: flex;
	flex-wrap:wrap;
}
.junior_banner li {
	width: calc(100%/3);
	padding:0 5px;
	box-sizing:border-box;
	list-style: none;
	align-content: center;
	margin-top: 24px;
}
.junior_banner li img {
	max-width:100%;
	height: auto;
}