If I change the class in the php file to heavyemphasis1 (or any other name - I've tried three different names) it does not work (the text goes to 'standard'). If I change it to heavyemphasis, the CSS works fine.
I am at a loss. I've spent 2½ hours trying to figure out why and I've run out of patience. What could possibly cause this behaviour?
Thanks for asking me to create the basic HTM page! It lead me to check the basics, including the fact that I was referencing my CSS file absolutely (including the domain name) and I was under the assumption that I was referencing it relatively. I was also doing my testing locally and I forgot to upload the CSS file to the domain, so my testing environment couldn't see the new CSS elements.
I just uploaded my CSS to my web server and it works fine again.