Hiding styles from Facebook

You can use Open Graph Protocol to define the data Facebook fetches from your site:

http://developers.facebook.com/docs/opengraphprotocol/

The metatag for the description has this form:

<meta property="og:description" content="my custom description for single post" />

You can use plugins, like

http://wordpress.org/extend/plugins/wp-facebook-open-graph-protocol/

to do it for you.

You can then debug your page here:

http://developers.facebook.com/tools/debug

to see how Facebook is fetching your page.

ps:
If you like code examples, I extracted the following code snippet from the above plugin (WP Facebook Open Graph protocol) that handles the og:description part and injects it into the header via the wp_head hook:

// do descriptions
if ( is_singular() ) {
    if ( has_excerpt( $post->ID ) ) {
        $wpfbogp_description = strip_tags( get_the_excerpt( $post->ID ) );
    } else {
        $wpfbogp_description = str_replace( "\r\n", ' ' , substr( strip_tags( strip_shortcodes( $post->post_content ) ), 0, 160 ) );
    }
} else {
    $wpfbogp_description = get_bloginfo( 'description' );
}
echo '<meta property="og:description" content="' . esc_attr( apply_filters( 'wpfbogp_description', $wpfbogp_description ) ) . '"/>' . "\n";