Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Watch Video

Posted May 10, 2015 2:13am by

So what causes the wrapper to center?

I got it to center, but I still want to understand more the intuition of why the wrapper centers. Because we didn't type in "center" in the code.

2 Answers

May 10, 2015 2:28am

When you set margin: 0 auto, you are telling the page to set the element to have a 0px margin top and bottom, and auto on left and right, which sets them to be the same, effectively centring the div.

August 15, 2015 8:48pm

To add on to Ryan's answer, the auto is also the reason the margins grow or shrink on the left and right sides of the page as you resize the window.

Posting to the forum is only allowed for members with active accounts.
Please sign in or sign up to post.