Width of Container CSS element only on pages with sidebars

Good day. I am using the Enfold-Gym demo content. I see in the CSS this code to control the padding on the left and right of the content on a page (regardless if its full width or if it has a sidebar)…

.container { padding: 0px 50px; }

On pages with no sidebars, this looks nice. But with pages with a right or left sidebar, I feel I could use those 50 pixels of padding on the left and right side to make the space for content on sidebar and made content area a little wider.

I changed the 50px to 20px and it looks good on pages with sidebars. However I would like to maintain the 50px padding on the non-sidebar pages that are set to full width.

Is there a way to have the left and right padding for the container element stay 50px for default full width pages, but have it 30px for only pages with sidebars?

Thank you.