Customized icon

Hi,
I designed a new icon, and put it in folder /aqua/images.
Then, in custom CSS, i wrote the code:
.icon-new {background: url(../images/icon-new.jpg);}
In a page, I put the code:
[feat_text title="Featured Title" icon="icon-new" href=""]Featured Text[/feat_text]

…but I don’t see the icon. Where am I doing wrong?

Thanks,
Albe