body {
	margin:30px;
	font-family: Arial, sans-serif;
}
h1,h2,h3 {
	margin:0;
	padding:0;
	text-align:center;
	font-size:4em;
}

.container {
		width: 1400px;
		padding: 0px;
		margin:auto;
		border:1px black solid;
		background-color:#ff0;;
	}

.box {
	width:100px;
	height: 100px;
	margin:10px;
	padding:5px;
	border:5px black solid;
	text-align:center;
	background-color:white;
	float:left;
}
.red {
	background-color:red;
}
.green {
	background-color:green;
}
.blue {
	background-color:blue;
}
footer {
	text-align:center;
	margin:0;
	padding:10px;
	border-top:1px black solid;
	background-color:#999;
	clear:both;
}

.bold {
    font-size:2em;
	font-weight:bold;
}

@media (max-width: 1400px) {
    .container {
        width: 840px;
    }
    body {
        background-color: gray;
    }
}

@media (max-width: 840px) {
    .container {
        width: 560px;
    }
    body {
        background-color: lightblue;
    }
}

@media (max-width: 560px) {
	.container {
		width: 140px;
	}
	body {
		background-color: orange;
	}
	header {
		font-size: 4px;
	}
	footer {
		font-size: 10px;
	}
}