Front Page Width

I am unable to adjust the width of my homepage, landing page or whatever you call it. I have read the guide, set up a child theme style.css and read the tips and notes. And I have carefully tried all of the suggestions available, for example in the following links:
https://wordpress.org/support/topic/changing-homepage-page-width-only/
https://wordpress.org/support/topic/full-width-post-pages-1/?replies=3
http://mtomas.com/wordpress-theme-support-consultation/

However, I am still unable to successfully adjust the front or home page to behave, width wise, as all the other pages.

My url is: http://www.thecomputerclub.org/

Could anyone help?