happy medium
noun [ S ] approving uk/ˌhæp.i ˈmiː.di.əm/ us/ˌhæp.i ˈmiː.di.əm/
折中方案
a state or way of doing something that avoids being extreme, often combining the best of two opposite states or ways of doing something
I try to strike a (= achieve a) happy medium when I'm on holiday, and spend half my time doing things and the other half just relaxing. 假期里我会争取休息做事两不耽误，用一半时间做事，另一半时间放松休息。