How is health calculated?

Thank you for this amazing app, i was just wondering how health was calculated. Ik it says based off screen time and snoozes, but I don’t understand what pre and post goal impacts are. When i click into brainrot first thing in the morning, my health is at smth like 80-90, even though i havent used my phone starting at 12am til when i woke up. I’ve refreshed it a couple times but the health still isn’t at 100 so it’s probably a me issue 😅. I was just curious as to how i can make it start at 100 each day was all.

Thank you.