how to I made CSS changes to Mystique template

Hi,
I made a child theme for the mystique theme (basically just created a mystique-child directory and created a style.css and put it in there), and i create a style.css file to override the mystique css properties. Now, the www.remarpro.com instructions say to import the parent’s “style.css” file in order to include the original styles in the child’s style.css so that one can change them, wiht the command:
@import url(../mystique/style.css)

But I looked at the “style.css” of the mystique theme, and it is empty. The real css styles are in the “core.css” file of the mystique template.
So the question is ,do I need to import the “core.css” file into my child theme’s style.css?

I am actually surprised, that my child theme’s css styles are working at all, given that I never imported any css file into the child’s style.css file? So what is going on? I thought that the browser would look into the child’s style.css file to grab the css styles.

Although when I looked at the index.html file with Firebug, I can see that the css style files that are being linked are the original mystique CSS files, basically core.css and another one.

So it seems to me that my child’s style.css file is NOT included in the index.html file and thus never looked at.

SO how can I make CSS style changes to the mystique theme WITHOUT having to manually change the core.css file, because that is really not optimal.

thanks