.container {
	display: flex;
	flex-flow: row wrap;
	box-sizing:border-box;
	margin-right:auto;
	margin-left:auto;
	max-width:1050px;
}
.box {
	flex:1;
	display: flex;	/* make the contents controllable by flexbox*/
	flex-flow:column;
	min-width: 240px;
	margin: 10px;
	padding: 20px;
	background-color: #000;
}