Footer Width & Distance between Widget Areas

Issues:

a) I want to bring the blue footer in the center of the site (like the whole site) by changing the width left (?), right (?)
b) If it possible to shrink the distance between the four colomuns of the widget areas in the footer

I have already checked style.css and footer.php files in my theme folder. Can someone help me? I have already searched in the portal for relative problems, but it seems that nothing helped me so far.

our website is: https://www.greeceonthego.com

thanks in advance!