$big-bg not displaying image


#1

I am trying to create a custom background using the instructions provided here:
http://learn.ionicframework.com/formulas/working-with-sass/

Unfortunately, the image is not displaying. My CSS is shown here:
.scroll-bg {
background: url($big-bg) no-repeat center center fixed;
background-size: cover;
}

The line added to the scss file is shown here:
$big-bg: ‘http://ioniconf.com/img/bg.jpg’;

It is my understanding that the url($big-bg) is supposed to update to the file path I designate in the scss file, correct? When the elements are inspected in the browser, the class is showing these attributes:
.scroll-bg {
background: url($big-bg) no-repeat center center fixed;
background-size: cover;
}

There seems to be something not connecting appropriately. Also, please note that the scss file does work, and other variables do update when changed. For example, I can change the color on a variable and it updates in the window.