Андрей Б.

@media screen and (min-device-width: 481px) {
   background-image: url(design/background.jpg);
}

.wrap {
	position: relative;
}
.wrap:before,
.wrap:after {
	content: '';
	position: absolute;
	top: 0;
	width: /*ширина изображения*/;
	height: 100%;
	background-repeat: repeat-y;
}
.wrap:before {
	background-image: url(...);
	left: 0;
}
.wrap:after {
	background-image: url(...);
	right: 0;
}

$("#amount2").val($("#slider-range-min2").slider("value") + '%');
$("#amount3").val($("#slider-range-min3").slider("value") + '%');

display: flex
   align-items: center
   flex-basis: 320px
   min-width: 350px

display: flex
align-items: center
flex-basis: 320px
min-width: 350px