Header, wrapper and content width

Hi and thanks for the great theme !
I’m trying to create my blog, offline for now (with InstantWP), and have the following problem :
The width of my blog is narrower than the Travelify preview.
I would like to get the same width of header and content as in the preview, and to have the featured image in the article preview full-content width, exactly like in the Travelify preview.
Could you please explain how to get this result ?
Thanks in advance !

@Anthelia,

All settings in our Theme demo are default ones with no custom code implementations. It should look exactly like in theme demo without any configuration. Of course you need to add your own content and images but that’s about it.

If you can’t make it work, please notify when your website is online so I can have a look, otherwise it is difficult to help without seeing your website layout.

Thanks, I’ll see how it looks when it’s online. Maybe it’s InstantWP…