Force related products into row of 3 on mobile

Site URL: https://www.tellemoi.co.uk

Hi there, trying to get my related products to show in a row of 3 on mobile for all product pages ( I have 4) , like it does on the computer

example:  https://tellemoi.co.uk/nailpolish/kamikhaki

Add to Design > Custom CSS > Then save & reload your site

/* related products */
@media screen and (max-width:640px) {
.ProductItem-relatedProducts-grid {
    display: grid;
    grid-template-columns: repeat(3,1fr);
    grid-column-gap: 10px;
}
}

Works perfectly. Thank you @tuanphan