Trying to match width of content+primary sidebar to primary menu width

@davidamericana-usa-com:
I am not quite clear to exactly what you want. You can add in your CSS code in Appearance=> Customize=> Theme Options=> Custom CSS box. This will override the main CSS file.

It is not good to edit core theme files as when you update the theme, the changes will be lost. If there are major changes, please do it via child theme. More info: https://catchthemes.com/blog/create-child-theme-wordpress/

Also, can you make your requirements clear maybe via a screenshot?

You can use dropbox or any image sharing sites like https://postimage.org/, http://imgur.com/

Regards,
Pratik

To match menu and content on static pages use following CSS code in Appearance=> Customize=> Theme Options=> Custom CSS box:

body:not(.home) .nav-primary{
    margin-left: 20px;
    margin-right: 20px;
}

To extend primary sidebar on to match content on homepage, use following code:

.home .sidebar-primary {
    padding-bottom: 28px;
}

Let me know how it goes.

Do you want the menu and slider to be same width as content in home page as well, to achieve that, remove the previous code and add in following:

#feature-slider, .nav-primary {
    margin-left: 20px;
    margin-right: 20px;
}

This should work on all pages. Previously, I thought you wanted it only on pages.

adding the padding to the .sidebar-primary had no effect though.
It should work, can you add the code in and then let me see how it looks on site?