header {
	background-image: url("../image/header/lessons.jpg");
	background-position: center 80%;
}

section#tips h4 {
	margin-top: 8px;
}

@media only screen and (-webkit-min-device-pixel-ratio: 2),
	only screen and (min--moz-device-pixel-ratio: 2),
	only screen and (-o-min-device-pixel-ratio: 2/1),
	only screen and (min-device-pixel-ratio: 2),
	only screen and (min-resolution: 192dpi),
	only screen and (min-resolution: 2dppx) {
	header {
		background-image: url("../image/header/lessons@2x.jpg");
	}
}

@media only screen and (min-width: 1500px) {
	header {
		background-image: url("../image/header/lessons@2x.jpg");
	}
}