Adapt block or make another block?

Question

Adaptive design

There is a menu block that is located in the sidebar, and on mobile devices it is displayed in the header as a scroll bar, as well as a lot of design changes. Should I adapt the menu, or make it a separate html block. The question of choice is, for example, can it affect seo?

Answer 1

SEO will not be affected. From my own experience, I will say that if the header is filled from the server (username, for example), then this is not very convenient, but in principle, it can be solved.
And from the point of view of correctness, they often do so. Feel free to type the second block.