body{
	width : 400px;
	height : 200px;
}

@media only screen and (min-width: 400px) and (max-width: 992px){
	
	body{
		background-color : green;	
	}		
}


@media only screen and (min-width: 992px) and (max-width: 1199px) {
	body{
		background-color : red;	
	}
}

@media only screen and (min-width: 1200px){
	
	body{
		background-color : black;	
	}		
}