Define zone-wrapper in Omega 4 and 960px I'm using omega 4 and i got problems. How can i define 960px in omega 4 ? should i define it in _grid.scss like this :

$grid: 12px ;
$gutters: 1/3;

$tab:44em;
$desk:77em;
$mobile:15em 35em; 


If it's true , how can i have something like omega 3 zone-wrapper with 100 % width ?!!!
If you are using Susy, something like that will do the job:

$total-columns: 12
$column-width: 6em;
$gutter-width: $column-width / 3;
$grid-padding: $gutter-width / 2;
$container-style: fluid;

html {
  font-size: 62.5%;
}

.l-page {
  @include container();
}