Build a "Superhero"-themed spawn fo...

Build a "Superhero"-themed spawn for a BoxPvP server, with one essential requirement: it must be a single building that is fully enclosed on all sides (walls + a complete roof) — I do NOT want an open-air structure or a facade with no sides. This should be a complete interior building, like a closed secret base. Entrance: - A circular archway/gate at the center of the front facade — a full circle carved into the wall, framed with a colored metallic border (Iron Block / Quartz), with lighting (Sea Lantern or Glowstone) running around the circle's edge - Walking through the circular gate leads the player directly into a central interior hall Exterior structure: - One single unified building (a large cube or rectangular block) with smooth, fully closed facades, in red/blue/turquoise colors