Hi,

Please 

• go to file sites\all\themes\md_hosoren\css\md_hosoren.css, add following code:

@media (max-width: 990px) {
.modal-quickview .commerce-add-to-cart .form-submit{
margin: 10px 0 25px;
}
.product-quickview-popup{
width: 100%;
max-width: 900px;
min-width: 0;
}
}
@media (max-width: 768px) {
.product-quickview-popup{
max-height: 480px;
overflow-y: scroll;
}
.product-quickview-popup .product-media{
float: none;
width: auto;
}
}

• Open file sites\all\themes\md_hosoren\js\md_hosoren.js,replace

if ($('.product-quickview-slider').length > 0) {
$('.product-quickview-slider').owlCarousel({
items: 1,
navigation: true,
pagination: false
});
}

with

if ($('.product-quickview-slider').length > 0) {
$('.product-quickview-slider').owlCarousel({
items: 1,
responsive: false,
navigation: true,
pagination: false
});
}