Screen time battles are ruining my evenings

Every single night at dinner my kids are sneaking phones, asking for more gaming time, and I feel like I'm just saying no constantly. We have rules but they test them constantly and honestly I'm exhausted by it. Sometimes I just let them do it because the fighting is worse than them being on screens. My wife and I aren't on the same page either which makes it harder. Looking for strategies that actually work because this can't be how the rest of childhood goes.