Website has stopped responding to changes in an external style-sheet

I'm working on a time-sensitive school project and I've been very grateful for this wonderful host but since about a week ago my website stopped responding to any changes in my CSS.. I researched the problem and most people say it's a caching issue and I used some caching tags in the head to no avail. I'm very new to any type of coding so I really don't know what it could be. Possibly the new caching system? Thanks in advance!

Other information that could help:

• I'm using the PHP and MySQL server services
• I have about 10 files in my main file and no folders

[valerpg]

I think it has something to do with altervista. My CSS doesn't update either even when CloudFlare is disabled.

[karl94]

Be sure to empty both your browser and CloudFlare cache.