Why does a bootstrap css for 2 sites not the same

I am creating a user and admin side of a website. The admin side of the website has "growIn" animation in the css, yet my user side css does not have this function. Why aren't the css the same?

Did you add the animation to that item in the User side? Remember, these things aren't the same exact items if they are on different pages and such. You need to add the effects to all pages and/or components involved. If you don't add the animation to one, it won't create the css for that one, why would it, it isn't needed if its not used right?

Just guessing here since we can't see the site.