.preview-wrap {
  position: relative;
  width: 100%;
  padding-bottom: 180%;
}
.preview_img {
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 2;
  -webkit-transition: opacity 0.1s linear;
  transition: opacity 0.1s linear;
}
@media screen and (max-width: 480px) {
  .preview_img {
    background-size: contain;
  }
}

/*добавил*/
.stock .slick-arrow {
    top: 50%;
    color: transparent;
    background-color: transparent;
    border: none;
    background-size: contain;
    transform: translateY(-50%);
}

.stock .slick-prev {
    background-image: url(/images/new/left-arrow.svg);
    left: -40px;
}

.stock  .slick-next {
    right: -40px;
    background-image: url(/images/new/right-arrow.svg);
}


.stock.stock--inner {
    display: block;
    max-height: 290px;
    opacity: 0;
    transition: opacity .4s .2s, max-height .4s .2s;
}

.stock.stock--inner.slick-initialized {
    opacity: 1 !important;
    max-height: 1000px;
    /* здесь указала точное значение, чтобы обеспечить плавность,
    если блок окажется больше ранее указанного max-h */
}

.stock.stock--inner .stock-item{
    display: block;
    flex: none;
    width: 100%;
    margin: 0 15px;
}
@media screen and (max-width: 640px) {
	.stock .slick-prev {
		left: -20px;
	}
	
	.stock  .slick-next {
		right: -20px;
	}
}