Is it correct to use several layout methods in one project?

Question

css

Hello, I am learning on my own, at the moment I have already mastered float-layout, I am studying flexbox, Bootstrap and Grid are ahead. I already have some practice, I want to ask to some studio, but it’s scary to show the code, and in particular because I don’t know the answer to the following question:
is it good practice to combine several types of layout at once?
Well, for example (of course, roughly speaking and purely hypothetically :) ), connect and use the bootstrap, make up the main screen, but the site header would be on flex, and the footer and some kind of "advantage" block would be float. Or will they laugh at this and point the finger?
Please tell us how you type? Thank you.

Answer 1

Position elements through float - a crutch and a forced measure (then there were no flexes / poor browser support). an example of using floats correctly is a picture that wraps around the text, for this they are needed.
about flex and grid - they can very easily live together ( smoke it : https://www.youtube.com/watch?v=s6RCsjcQADc&t=2786s )
if you make up on bootstrap - then make up all sections with bootstrap, and everything inside the columns - you can do anything (flex / grid)
again, watch the video that I threw off - they will tell you everything there)