@media (max-width: 767px) {
    .products_block .product-miniature, 
    .product-list .product-miniature {
        width: 48% !important;
        float: left !important;
        margin-right: 2%;
    }
    
    .products_block .product-miniature:nth-child(even),
    .product-list .product-miniature:nth-child(even) {
        margin-right: 0;
    }
}