Maximum battery capacity down to 97% on a macbook air i bought last year

I've had my macbook air M1 chip since october i think. And it's down to 97% maximum capacity.

I wanted to know if this is normal or if I should be managing my use better. Typically only put the mac to sleep since i use it everyday. And also normally leave lots of tabs open in safari but trying to close those more often

I use my macbook air to charge my iphone 13 and the maximum capacity on that is now 99%. i got it about a month later than the macbook air i think (did a pre-order).

i try not to overcharge my phone or my laptop but i get paranoid about my phone not having enough charge when i need it. i normally take my phone off the charger once it hits 100% but occasionally i'll leave either of them on the charger overnight