How Do I Remove the Box Shadow From A Button In The Upfront / Spirit Themes?

Hello, I would like to know how to remove the box shadow from buttons in the Upfront / Spirit theme. I am currently working on a website at http://www.freerecordingschool.com. I have created a button that I like, except for the white box shadow under it. I've tried a few bits of CSS that I know, most specifically:

.upfront-button {
-webkit-box-shadow: none;
-moz-box-shadow: none;
box-shadow: none;
}

&

.upfront-button a {
-webkit-box-shadow: none;
-moz-box-shadow: none;
box-shadow: none;
}

Neither is working for me. Any help would be greatly appreciated.

- Samori Coles