Page Padding

Hi I have opened a couple tickets about page padding under the main banner- each time my ticket gets closed for some reason- I was given this code and it doesn’t seem to work when the browser window if fully open- I just would like there to be more padding on the left and right of the main body copy on each page- its too wide – and becomes hard to read….

#after_section_1,
#after_submenu_1{
padding:0 100px;
}