My countdown does not work anymore for Mozilla Firefox.

Question

Today, it gives me that :
NaNd NaNh NaNm NaNs NaNms
View this code :
https://code.sololearn.com/WQ3CYiTzEj6O/#html for Mozilla

Answer 1

Mozilla Firefox disables JS
(translated using google translate)

Answer 2

remove all those -webkit- from css and then add
<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
in html

Answer 3

Mm. What is your nationality?

Answer 4

UZ or FR