Hi I am trying to make the layout… 

Hi,

I am trying to make the layout of the homepage go from 3 columns to 2 columns (and then to 1) as the screen gets smaller.
I was wondering if there is a simple way to achieve this? At the moment, the homepage goes directly from 3 columns to one column when the screen is narrower than 1200px.
If you could just tell me which CSS selector to use in my media queries, it would be great!

Thanks :)