Use the reference image as the main...

Use the reference image as the main design guide. Create a compact Minecraft dimension train lobby based closely on the reference. 27x27 blocks, maximum height 11 blocks. Single floor, symmetrical stepped octagonal shape. Four train entrances at front, back, left and right with rails extending outward. Red Team and Blue Team areas on opposite sides. Dark steampunk train interior with deepslate, dark oak, copper, glass and lanterns. Purple portal lighting around the entrances. Keep the structure compact and fully buildable with vanilla Minecraft blocks. No NPCs, no text, no second floor, no smooth curves, no floating parts, no oversized areas.