.product__text-descr-hidden {
    max-height: 85px;
    overflow: hidden;
    position: relative;
    -webkit-transition: -webkit-transform .3s ease;
    -o-transition: transform .3s ease;
    transition: transform .3s ease;
    transition: transform .3s ease,-webkit-transform .3s ease;
}

.product__text-descr-hidden.active {
    height: auto;
}

.product__text-descr-hidden.active::after {
    height: 1px;
}

.product__text-descr-hidden::after {
    position: absolute;
    content: "";
    right: 0;
    bottom: 0;
    height: 30%;
    width: 100%;
    z-index: 99;
    background: -webkit-gradient(linear,left bottom,left top,color-stop(30%,rgba(45,45,45,.9)),to(rgba(45,45,45,.3)));
    background: -o-linear-gradient(bottom,rgba(45,45,45,.9) 30%,rgba(45,45,45,.3) 100%);
    background: linear-gradient(to top,rgba(45,45,45,.9) 30%,rgba(45,45,45,.3) 100%);
    background: var(--bg-color-gradient);
}

@media (max-width: 425px) {
    .product__text-descr-hidden {
        max-height: 50px;
    }
    .product__text-descr-hidden.active {
        max-height: 100%;
    }
}