Theme doesn't display correctly on Firefox but it does on Chrome

[daniela-angulo]

Hi!
I have been using this awesome theme to build my website and it was working fine when I looked at it on Firefox but now it looks like plain text when I opened it.
I thought it was my code but not even your official template displays correctly.
However, if I use Chrome, everything works smoothly.
What could it be the problem?

Thanks.