Skipped heading level
Why it matters
Jumping from h1 to h3 breaks the outline that screen-reader users navigate by (Lighthouse: heading elements are not in a sequentially-descending order).
Fix
Use the next level down and style it with classes.
Credit
From Deque
The axe rule heading-order says heading levels should only increase by one.
From W3C Web Accessibility Initiative
The WAI headings tutorial and WCAG 1.3.1 treat headings as structure that assistive technology navigates.