Make page full width

Hello,

I’m currently trying to make a page full width, so there’s no border on the left and the right.

I found some threads here already, but none of them seem to work…

I already tried this:

.page-id-221 #secondary, .page-id-221 #sidebar_bg {
    display: none !important;
}
.page-id-221 #header, .page-id-221 #primary, .page-id-221 .content {
    width: 100% !important;
}
.page-id-221 #header {
    padding-left: 0 !important;
}

and I also tried to play with the maximum container width in Enfold Settings, but also, no success, no matter if I set it to a high px amount or to 100%….

How can I make my page full width?.. It would be okay to have every pages full width as well.