Reply To: Fullwidth for all items on the page

[7Theme Support]

Ah, ok, first your wrote you want to make it responsive and 100% width, so I thought you want to have it only on mobile phones or smaller screens.
You can add this code in WP Admin -> Appearance -> Theme Options -> General -> Extra CSS Content:

.inner {
width:100% !important;
}

This will make all entries 100% width.