Automatic width in the stack

Hello I am new user of the theme Foundation
I have a request:
the width of the layout is automatically put on setting to 960 pixels
Where action is taken to change this width?
To me some layout it would need 700 pixels
It would be really handy to be able to change this width
Thank you in advance for your cooperation

The Foundation theme itself has no maximum width. The sites maximum width is controlled by the site styles stack, which defaults to 1000px (see pic below).

You can also control the width using the column stacks by selecting either site width which will use the Site Styles value, or individual width settings per column of which there are many choices.

thanks a lot
I had just seen well this panel;-)