strapvert child theme edits aren't working

I’ve added a child theme to StrapVert. I believe it’s installed correctly and is active, however any changes I try to make on the child style.css page don’t seem to do anything.

For example, I’d like to edit the footer. I’ve tried copying this into the stylesheet:
#site-generator{display: none;}

and I have also copied the footer.php from the parent theme into style.css and edited/deleted text.
Neither of these had any effect; it still shows the complete/original footer.

I’ve also cleared my cache, the only plugins I have are headspace and calendar, which I don’t think would effect cache.

Am I missing something?
lsstringschool.com

Thanks.