@media (max-width: 959px) {
    .wp-singular div.product .product_title {
      font-size: 20px!important;
    line-height: 24px !important;
    text-transform: uppercase!important;
    }
    .woocommerce div.product .product_main_infos .grtr_product_header_mobiles .price, div.product .product_main_infos .grtr_product_header_mobiles .price{
        font-size: 18px!important;
    }
}