Nuclear missile WAITING IMAGE

[Midonik]

This is a fun mode only technology. It can be research in human underground fortresses (mega buildings), upgrading them into underground nuclear silos (or something like that). Those are exactly the same, but they can fire an intercontinental nuclear missile once a game. It has 20 range and high damage (like 80) with aoe of 3, decreasing by 50% with every tile from epicenter, to keep things simple. It can be researched in multiple mega buildings, so you get as many of them as your build limit. You can also delete your megas and build them again, however the technology should cost around 20 turns so it will be hard to execute in practice.
We need an image for the tech, and also an image for the underground nuclear silo - it should just be the underground fortress with a missile launching pod in the centre.