Carousel/Slider from WordPress Gallery using Flickity (update CSS)

style.css

.gallery-carousel {
	display: block;
    margin-bottom: 1em;
}

.gallery-carousel:not(.columns-1) .blocks-gallery-item:last-child {
	margin-right: 16px;
}

.gallery-carousel .blocks-gallery-item {
  height: 200px;
}

.gallery-carousel .flickity-viewport {
  width: 100%;
}

@media (min-width: 600px) {

	.gallery-carousel.columns-3 .blocks-gallery-item:nth-of-type(3n),
	.gallery-carousel.columns-4 .blocks-gallery-item:nth-of-type(4n),
	.gallery-carousel.columns-5 .blocks-gallery-item:nth-of-type(5n),
	.gallery-carousel.columns-6 .blocks-gallery-item:nth-of-type(6n),
	.gallery-carousel.columns-7 .blocks-gallery-item:nth-of-type(7n),
	.gallery-carousel.columns-8 .blocks-gallery-item:nth-of-type(8n) {
		margin-right: 16px;
	}

}

.gallery-carousel .flickity-prev-next-button.previous {
	left: -60px;
}

.gallery-carousel .flickity-prev-next-button.next {
	right: -60px;
}

@media only screen and (max-width: 768px) {
  
	.gallery-carousel.columns-1 .blocks-gallery-item {
		width: 50%;
	}
  
	.gallery-carousel .flickity-prev-next-button.previous,
	.gallery-carousel .flickity-prev-next-button.next {
		display: none;
	}

}

@media only screen and (max-width: 480px) {
  
	.gallery-carousel.columns-1 .blocks-gallery-item {
		width: 100%;
	}
  
	.gallery-carousel.columns-1 .blocks-gallery-item:nth-of-type(1n) {
		margin-right: 0;
	}

}