Question to any lawyers here: is halakha (most similar to) a common or civil law system?

I’m secular, so I don’t know much about halakha. From the little that I do know — it seems like back in Ancient Israel, there were multiple levels of courts, with the Sanhedrin as the “Supreme Court” (were the different levels courts of appeals?). Now though, we just have batei din, and as far as I can tell (am I wrong?) there aren’t any higher or lower levels.

Now, let’s say I’m part of a beit din, and there’s an issue similar to one the Sanhedrin (or another beit din) ruled on. Am I bound to follow their precedent (as in a common law system, where judges’ rulings become part of the law), or can I rule differently (as in a civil law system)?

If the Sanhedrin were to be re-formed, could they rule differently than prior Sanhedrins, much as the Supreme Court can change law by ruling differently?

Am I missing something major by coming at this from a secular legal framework?