Responsive View Grid

I'm using a 3 columns Grid View. Here is the code I'm using <a href="[wpv-post-url]">[wpv-post-featured-image]<br />[wpv-post-link]</a>
The page look good on desktop but it's not responsive. In cellphone, instead of the 3 columns, I want to have them in 1 column (one item on top of another). How to make the grid layout responsive?

Thanks. Help needed please.