"Create a black-and-white hand sketch of a single underwater habitat pod design with a circular form. The pod should have a multi-layered skin resembling flexible piping, featuring large, round viewing windows that look out into the deep sea. Include subtle shading to indicate depth and curvature, and use fine line work to highlight the pod's structural details. The interior should show functional elements like curved seating areas, built-in storage, and soft lighting fixtures, emphasizing a livable, cozy atmosphere inside the circular space."