Text invisible in Mozilla Firefox

Hi Team,

I have an issue ONLY in Mozilla Firefox.

As you can see in this URL : https://www.sudprojet.com/contact/
When you’re typing some text, its invisible, and i don’t understand why.

It’s working perfectly in CHROME and IE.

How can i fix it?

Thanks in advance

https://www.ads-software.com/plugins/contact-form-7/