[successful23]

Honestly, this feels like a long-overdue cleanup. The outline algorithm always sounded good on paper, but in practice, it just created confusion - especially when different tools and screen readers treated headings differently.

Dropping the UA styles makes things more predictable: <h1> means <h1>, no matter where it lives. Yeah, the partial rollout across browsers is going to be rough - debugging across inconsistent browser behavior is going to be a nightmare. Still, if this pushes devs to rely less on implicit styling and more on their own structure, they can now take control of heading semantics more properly.