My new garden bed from Bunnings, to start growing some veggies, and it needed an upgrade, so, I just made a greenhouse top for it, till the seed are ready to face the world, then it just lift off when the seedlings get bigger.
I used screws, nuts and bolts, 2 hinges clear silicone, duct tape 4 angle corner braces and Sunlite Clear Twinwall Polycarbonate Sheet


