Hello All,

I am trying to customize the theme for my Tumblr, and I would like to have a responsive masonry layout. Now the theme that I have found is almost perfect except for the fact that I would like to have the 4th and 11th posts(photos) expanded to be a larger image.

I am unsure of the code to enlarge these containers.

A link for my site can be found here:

obeliskintl dot tumblr dot com

Thank you all graciously in advance.