If you’re getting unexpected results on a web page you’re laying out, like not seeing changes you’ve just made, it could be that your browser is simply showing you what it still has in its memory, or “cache”, which is French for “hide”,
as in a hiding place, or as in “The cat had a cache of fun toys under the couch where only she could get at them. That is, until cleaning day. Silly Humans!” Anyway . . .
To clear Firefox’s cache, go to Tools/Option/Network and click on the “Clear Now” button in the center of the dialogue, then click “OK” to close the dialogue box. Switch to the tab containing the suspect page and hit F5 (Windows or Mac) to refresh it.