Connecting bootstrap to an existing site?

Question

css

Hello, there is a ready-made site that needs to be edited, added something, and expanded functionality. Is it possible to connect bootstrap to an already finished site in order to carry out all the work through it? And if yes, how to do it. I'm still a beginner, so I'm waiting for your answers.
Thank you.

Answer 1

In the head, simply add the bootstrap file (or a link to it) with the second style:
And after that you can already add bootstrap classes to the html file.