Thanks, Abhishek! I've added your code directly on the CMS Page (just adjusted the CSS to be inline) and it worked! Now I just need to implement the counter to count from today to a specific date on the script.

Hello, Prince! Thanks for your answer. As I said, I do not have access to add archives on the server. So this way is not possible for me. I need to found a way where I can do everything just in the CMS Page Editor or at least, call a JS that is uploaded on another server.