I tested and was able to login to your cPanel successfully using the latest versions of: Firefox, Chrome, and Safari.
We are happy to assist you, but would need more specific information to replicate the error, such as: what type of browser you are using, and what version.
Sometimes the ports are blocked by your network, try accessing cPanel via port 80 by navigating to:
http://cpanel.domain.com (be sure to use your actual domain)
Also, make sure you are using the correct cPanel username
If you have any further questions, feel free to post them below.