Does the search engine see h1-h3 tags hidden by CSS styles?

Question

Search Engine Optimization

There is a popup in the footer of the page. By default they are hidden with display:none.
These windows have titles framed in h1-h3 tags. Callback. Thank you for your application and more.
Should I change tags to , span and others? Does the search engine see them? Thank you.

Answer 1

it’s worth changing it
’s called “poor-quality content” at least, or even manipulation

Answer 2

Label these blocks in section. A section should have a title.
Checkmate, PS.

Answer 3

H1 must be once! The rest, how many! If you don't have H1 in the module window, don't touch anything