.test-unchanged-properties {
	background-1: url("img/test.png");
	background-2: url(my-img-print.png) top left no-repeat red;
}

.test-changed-properties {
	background-image-1: url(img/test.png);
	background-image-2: url(img/test.png);
	background-image-3: url(img/test.png);
	background-image-4: url(img/test.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-changed-properties {
	background-image-4: url(img/test-2x.png);
}
}

@media (-webkit-min-device-pixel-ratio: 6.25), (min-resolution: 600dpi) {

.test-changed-properties {
	background-image-4: url(my-img-print.png);
}
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-changed-properties {
	background-image-3: url(img/test-2x.png);
}
}

.test-variables {
	background-image: url(img/test.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-variables {
	background-image: var(--test-image-2x);
}
}

@media (-webkit-min-device-pixel-ratio: 3), (min-resolution: 288dpi) {

.test-variables {
	background-image: var(--test-image-3x, url(img/test-var-fallback-3x.png));
}
}

.test-mixed-units {
	background-image-1: url(img/test.png);
	background-image-2: url(img/test-2dpcm.png);
}

@media (-webkit-min-device-pixel-ratio: 1), (min-resolution: 96dpi) {

.test-mixed-units {
	background-image-2: url(img/test.png);
}
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-mixed-units {
	background-image-1: url(img/test-2dppx.png);
}
}

.test-mixed-order {
	background-1: url(../images/bck.png);
	background-2: url(../images/bck.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-mixed-order {
	background-2: url(../images/bck@2x.png);
}
}

@media (-webkit-min-device-pixel-ratio: 3), (min-resolution: 288dpi) {

.test-mixed-order {
	background-2: url(../images/bck@3x.png);
}
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-mixed-order {
	background-1: url(../images/bck@2x.png);
}
}

@media (-webkit-min-device-pixel-ratio: 3), (min-resolution: 288dpi) {

.test-mixed-order {
	background-1: url(../images/bck@3x.png);
}
}

.test-no-url {
	background-image-1: url("img/test.png");
	background-image-2: url("img/test.png");
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-no-url {
	background-image-2: url("img/test-2x.png");
}
}

@media (-webkit-min-device-pixel-ratio: 6.25), (min-resolution: 600dpi) {

.test-no-url {
	background-image-2: url("my-img-print.png");
}
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-no-url {
	background-image-1: url("img/test-2x.png");
}
}

.test-webkit-prefix {
	background-image: url(img/test.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-webkit-prefix {
	background-image: url(img/test-2x.png);
}
}

@media (-webkit-min-device-pixel-ratio: 6.25), (min-resolution: 600dpi) {

.test-webkit-prefix {
	background-image: url(my-img-print.png);
}
}

@media (min-width: 1000px) {
	.test-within-mq-1 {
		background-image: url(img/test.png);
	}
	@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
	.test-within-mq-1 {
		background-image: url(img/test-2x.png);
	}
	}
	@media (-webkit-min-device-pixel-ratio: 6.25), (min-resolution: 600dpi) {
	.test-within-mq-1 {
		background-image: url(my-img-print.png);
	}
	}
}

@media (min-width: 768px) and (max-width: 1024px) {
	.test-within-mq-2 {
		background-image: url(img/test.png);
	}
	@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
	.test-within-mq-2 {
		background-image: url(img/test-2x.png);
	}
	}
	@media (-webkit-min-device-pixel-ratio: 6.25), (min-resolution: 600dpi) {
	.test-within-mq-2 {
		background-image: url(my-img-print.png);
	}
	}
}

.list-1 {
	background-image: linear-gradient(#4444, #8888), url(img.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.list-1 {
	background-image: linear-gradient(#4444, #8888), url(img@2x.png);
}
}

.list-2 {
	background-image: url(img-a.png), url(img-b.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.list-2 {
	background-image: url(img-a@2x.png), url(img-b@2x.png);
}
}

.test-valid-data-url {
	background-image: url(data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

.test-valid-data-url {
	background-image: url(img/test-2x.png);
}
}

.test-invalid-data-url {
	background-image: image-set(data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==, url(img/test-2x.png) 2x);
}

to-clone {
	background:url(img/test.png);
}

@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {

to-clone {
	background:url(img/test-2x.png);
}
}