I would like someone with more experience on the matter to take a look and point out to any shortcomings of my solution. As evident I have used three media queries in my solution: JSFiddle - Code Playground
This is a more advanced version for the cards. It places as many 300px wide cards per row that fit and stretches them evenly to use all the space. On medium screens you would automatically get two columns and on larger one three (or even more). You wouldn’t need any other grid definition for the cards class. Cool, isn’t it?