frontend-design

A default is a decision nobody made, and an interface nobody looked at is unverified. Interfaces go wrong at those two points. A value arrives from the model's habits or from a framework's stock settings and ships unexamined. Then the result is checked by reading markup instead of looking at the page.

Fix the design, not the detection. A pattern is a defect when nothing chose it, never because it resembles other sites. The navigation, the form, and the table a user already knows are what make an interface usable.

Find what already decides

Before any visible choice, establish what has already made it. Take the first that holds.