Child Theme breaks if I make any changes

I’ve set up a child theme but if I add anything to the style.css, the theme breaks. Here is the code I am trying to use to change the page title text. If I take out everything below the @import line, the theme works again but anything I add below there breaks it. What am I doing wrong?

/*
Theme Name: Twenty Eleven Child
Version: 1.0
Description: A child theme of Twenty Eleven
Template: twentyeleven
*/

@import url(“../twentyeleven/style.css”)

.singular .entry-title {
font-size: 26px;
font-weight: normal;
line-height: 30px;
}