A. There must be more shade than light in the sukkah, but some light must be allowed to penetrate.
There is a lesson for life here. Life is never completely dark and black. There is always at least a glimmer of light and hope to relieve the darkness.
No-one should be tempted to believe that everything will always be black, negative and doom-laden. Even in the worst moments of suffering, a person must refuse to give in to total despair.
Human history has known many dark ages, but this is not the end of the story. God does not abandon His creation. Redemption, however delayed, will arrive. It may take time, but the light of messianic fulfillment will shine.