custom shortcodes css styling help needed

I'm implementing some simple custom shortcodes to allow my client to set quotes in a custom box with a quote image. I was able to get the quote shortcode to work but the CSS coding is not appearing. I've tried placing my custom shortcode CSS everywhere I can think.
I've tried pasting the code and and I've tried pasting an import statement in the following locations to no avail:
1) /wp-content/themes/atahualpa353/styles.css,
2) /wp-content/themes/atahualpa353/css.php,
and in the Add HTML/CSS inserts section of the Atahualpa Theme Options section.

I'm clueless at this point and need some help ... please??

Thanks,

ks