Child Theme Not Working – Created After Previous Theme Edits

A couple of weeks ago, I installed a website theme on my localhost, added text and pages and changed some colors.

Today I created a Child Theme and followed the Codex instructions (I thought) exactly. When I Activated my Child Theme, the background colors of the site went gray (before there was a gradient green background). I went to Settings, Permalinks and changed the setting to Custom, Saved changes — but nothing changed.

Here is what I did. Can anyone tell me why this doesn’t work?

In mysitename/wp-content/themes I created a folder called
twentytwelve-child

Inside that folder I created a file called style.css. Here is the code inside the css file:

/*
 Theme Name:   Twenty Twelve Child
 Theme URI:
 Description:  Twenty Twelve Child Theme
 Author:       My Name
 Author URI:
 Template:     twentytwelve
 Version:
*/

@import url("../twentytwelve/style.css");

/* =Theme customization starts here
-------------------------------------------------------------- */