Ask HN: How do you manage your child's screen time?

I’m a single parent to a 13-year-old who just got an iPhone, and I’m finding Apple’s parental controls leave a lot to be desired. I'd like my kid to engage in activities outside of school, sports and screens but it's hard to motivate him when the devices are so addictive.

I’m trying to figure out: - How much screen time is actually reasonable? - What should I be okay with him accessing vs. not? - And how do you enforce your rules—tech, conversations, or something else? - What works for you when trying to encourage other activities like reading, outside time, building things, etc.

It seems simple, but I feel like I’m missing a clear approach and philosophy. Would really appreciate how others think about this.