Markdown Headings: What's H1, H2, H3 and When to Use Them
Every page should have exactly one H1 — the page title. H2s divide the page into major sections. H3s subdivide those. Deeper than H4 usually signals a structure problem.
Skipping levels (jumping from H2 to H4) breaks assistive tech navigation. Keep the hierarchy clean and your content outlines itself.