Hello I have the same problem that are showing in your demo
demo.flexiblewebdesign.com/cleanmart/index.php?option=com_virtuemart&view=cart

when you want to enter your coupon code it then type in white so you don't see what you are writting

how to solve the problem?

the problem happen when you want to enter your login detail in the same page

thank you

hmm, that's weird that nobody have reported this problem before. This problem only happens in Firefox.
Open this CSS file:
/templates/YOUR_TEMPLATE/html/com_virtuemart/assets/css/flexible.css

scroll to the bottom and include this lines:

You will be good to go.

Regards.

thank you it works!

you're welcome. I am glad it works.

Case solved, topic is closed.

regards