Balance

To acquire balance means to achieve that happy medium between the minimum and the maximum that represents your optimum. The minimum is the least you can get by with. The maximum is the most you're capable of. The optimum is the amount or degree of anything that is most favorable toward the ends you desire.
—Nido Qubein

bal·ance - A state of equilibrium; equal distribution of weight, amount, etc. / OPPOSITE - Imbalance; instability