4 Button redstone lock (world save)

Hello! this is my newest project it is a 4 button redstone lock where all 4 buttons have to be hit to turn it on, it has been tested to work many times and all buttons are currently off, "what do you mean buttons are off? i thought buttons cant be off?" yes that is true but once you get to my level of skill with redstone you can make a button act better than a lever so one press turns something on or off, anyways I will make better redstone devices and more projects soon, so sub or diamond, i really would like a diamond if you at least saw this and thought it was good, oh and there is a door so you can go down and see the redstone so you can copy it into a server you go on so someone has to find all the buttons to open it, you can just turn off one button to make it close. One more thing a jungle is nearbye.

Additional Notes

I did not get this from youtube I just took my knowings of and gates and t-flip flops and put them together.