selecting the nav element in CSS responsive page?

Hello I have been having issues with selecting the nav element in my CSS responsive page. I am following Nick's tutorial and as far as I can see I have followed completely however when using the mediaquery techniques it won't allow me to select the nav element? always highlighted in red. Here is a copy of my code.

@media screen and (min-width: 480px) {

/****************************
Two column layout
*****************************/

#primary { width: 50%; float: left; } #secondary { width: 40%; float: right; }

  /****************************
Page: Portfolio
*****************************/

#gallery li { width: 28.3333%; }

#gallery li:nth-child(3n + 1) { clear: left; }

/**************************** Page: About *****************************/

.profile-photo { float: left; margin: 0 5% 80px 0; }

}

@mediaquery screen and (min-width: 660px) {

/****************************
Header
*****************************/

nav { background: none; float: right; font-size: 1.125em; margin-right: 5%; text-align: right; width: 45%; }

}

I would be grateful if someone could tell me what I'm doing wrong.

Regards Steve