Need Help with CSS Margins, i added a outline and colums go down

Hi there i added some outline to a 3 colums portfolio and now it became a two colums cause of the outline the third colum is going to another line, ive been looking were is the code to set the margin between colums 2px smaller, but i have tried everywere with no luck, anyone can help point me in the right direction to do this?

here link for homepage were you can see the error
http://goo.gl/AzpBKR

and the portfolio
http://goo.gl/2i9F3V