Hello,
The best way to add your custom styles (css) is to fill them into Custom Head Styles field in the administration - here is a
guide how to find it.
The css code you need to paste there is:
.quickViewWindow .related-products-grid .item-grid {
height: auto;
}
.quickViewWindow .related-products-grid .item-box {
width: 206px;
}
.quickViewWindow .related-products-grid .item-box:nth-of-type(3n+1) {
clear: left !important;
}
.quickViewWindow .related-products-grid .item-box .details {
height: auto;
}
.quickViewWindow .related-products-grid .add-info {
display: inline-block;
margin-top: 5px;
}
.quickViewWindow .related-products-grid .productQuantityDropdown,
.quickViewWindow .related-products-grid .productQuantityTextBox {
display: none;
}
Notice that now all the related products will show up.
I have made three items in row because if there are four there is no enough space for the button and the item price.
I hope that will help you.