Is it necessary to keep the same header and footer on different pages of the site?

Question

Search Engine Optimization

Hello.
There is an old online store site.
We want to add several landing pages and a blog to it.
Accordingly, to make it more convenient to transfer weight between pages, I would like to arrange them as subdirectories, and not on subdomains.
Those. the landing page will be at site.ru/landing/ and the blog site.ru/blog/
However, the design of the landing pages and blog does not involve the use of the standard header and footer used in the rest of this online store.
How correct, from the point of view of SEO, to make several different header and footer?
On the plus side, usability will improve.
Of the minuses - probably the links in the header and footer will not be completely cross-cutting.
What do you think?

Answer 1

Quite correct. Nothing bad will happen. On the part of Seo, it may even be a plus if behavioral factors improve.

Answer 2

PS absolutely do not care about your links and structure. This is only important for usability.
The main thing for the PS is that the tags and "keys" correspond to the content .