Content width of home page different than other pages

Hi,

I am using The 7 theme and looking to make my homepage content width to 1250px while the rest of the site is 1050px.

I have gone into the general settings of my theme and set the content width to 1050px, however I can’t seem to find out how to change just the one page.

When I post code that I found when searching around like this (6 being my homepage id) I don’t get the result I am looking for but rather all of the content shifted over to the right with some ugly white space.

.page-id-6 .content {
width: 1250px;
}

Any help would be appreciated, thanks