zeaks

The page width in Twenty Eleven, depending on which layout you are using, is set by.

/* regular layouts */
#page {
	max-width: 1000px;
}
/* One column */
.one-column #page {
	max-width: 690px;
}

If you’ve already created your child theme, just add either of those to t, and set the max-width to whatever you want.

You don’t need to copy the entire style.css, the only thing you need is a folder, and your own style.css with this info in it.

/*
Theme Name: My Cool Theme
Theme URI: http://yoursite/yourtheme
Description: A child theme of 2010-11 default WordPress theme.
Author: You
Author url: http://yoursite.com/
Version: 1.0
Tags: black, blue, white, fixed-width, custom-header, theme-options
Template: twentyeleven
*/
@import url("../twentyeleven/style.css");

Then you add your custom CSS. (makes it much easier to see your changes than adding the entire stylesheet)

If you modify a file, for Example – In my theme I changed content.php to use excerpts on the main page.

So I Copied content.php to my child theme folder and made my changes to that.

Your child theme will use any files in its folder, if they are not there it will look to the parent theme and use those instead.

Copying the folder and renaming it is at least better than editing the original.
The best is to use a child theme, then your changes are easy to see, will never be overwritten during an upgrade of WordPress and your child theme will continue to receive updates to the parent theme.

Site key isn’t working for me.

Do you have any type of caching plugin? Some of them turn off cache for logged in users, which would explain why you can only see your changes when you’re logged in. W3 Total Cache does it I think. If you do, empty the cache and refresh your browser.

It’s in the root

Can you link your style.css or site