b-image & device pixel ratio

Графика.

.page__header {
	position: relative;
	background-image: url(img/pic.png);
	width: 1440px;
	height: 800px;
	background-size: 1440px 800px;
	margin: 0 auto;

	@media (min-resolution: 2dppx) {
		background-image: url(img/pic@2x.png);
	}
}