In order to get clear calorie surplusses/decifits per day, I've recently started to do cardio and lifting on seperate days.

I'm concerned though: if I do cardio (enough for a decent calorie deficit that day) roughly 24 hours after I lift (having a large calorie/protein/carb surplus the day of the lifting), does that mess with my protein synthesis for the previous day?

Aside from that, if I go to the gym up to 4 days in a row, alternating lifting with cardio, am I overtraining? I try to avoid lifting two days in a row, but I'm curious if it's OK to do cardio and lifting back-to-back or if I really need a COMPLETE rest day.

I'm trying to pack on a good 5-10 pounds of muscle in the next couple of months, but I still have maybe 5 pounds of fat I want to get rid of for definition. Any advice would be appreciated.