I’m trying to make a landing page that is not full-width like the one in the demo: http://jkreativ.jegtheme.com/interior/
But when I use the landing page builder, I can’t find a way to make the page like that. The page always turns out full-width.
To achieve that, you will need to use boxed content. You can find this option on Customizer > Navigation Position > Choose Top Navigation > check Boxed Content option. Please note, Boxed content only available when you’re using top navigation.