Create a black-and-white outline illustration in a perfect square 1:1 ratio for a children’s spooky cozy coloring book. A cute skeleton wearing a sweater relaxes in a pumpkin-shaped bathtub filled with bubbly water, holding a cup of hot cocoa. A rubber duck floats in the tub. The bathroom has a ghost-shaped towel, a shower curtain with bone patterns, and shelves with bottles labeled with skulls. All objects and characters should be drawn with bold smooth outlines, clean white interiors, no solid black fills, no shading, and no grayscale. Keep the background elements minimal and light for easy coloring.