How enlarge my blog page

Hello All,
I want to enlarge my page site but , despite having followed SALSATURATION INSTRUCTION, I’m not able to do that, so i doing something wrong.

I installed custom css, and i have include the following code in css manager area and in custom.css as well.
Please could you help me?
the link i realated the site, i wants to reduce the backgroud blue area and enlarge pages.
https://drive.google.com/file/d/0B9Mo48uzPNwWRE1PcmV0VUpaZ2s/edit?usp=sharing
Currently the site in maintenance but i can open it if you need.
Thanks in advance
Romeo

@media screen and (min-width: 960px)
body .site {
padding: 24px 24px 0;
margin-bottom: 24px;
}

@media screen and (min-width: 768px)
.site {
max-width: 1040px;
}