Rainbow 3D Kabutomushi Beetle

Create a single-subject 3D digital artwork of a cute stylized Japanese rhinoceros beetle, a kabutomushi, floating diagonally on a pure black background. The beetle should have a soft toy-like, rounded, glossy clay/plastic surface with smooth inflated forms and no hard textures. Show exactly 1 beetle with 6 segmented legs, 2 small antennae, 2 round side eyes, 1 large forked Y-shaped horn rising from the head, and 1 smaller cone horn on the thorax. Angle the body from upper left to lower right, with the head near the upper left and the abdomen extending downward right; use a three-quarter top view. The shell has two large rounded wing covers divided by a central groove, a domed orange-yellow thorax, and bulbous magenta-purple-blue body segments. Use vivid rainbow gradient lighting: cyan and teal along the left edges, saturated pink and magenta through the middle, warm orange and yellow highlights on the upper shell, and violet-blue shadows underneath. Add soft rim lighting and subtle bloom while keeping the background completely black and uncluttered. Include a small elegant signature/date in the lower-right corner reading {argument name="date text" default="July 27, 2026"} above a cursive artist signature {argument name="signature text" default="Oyagi"}. Overall mood: adorable, futuristic, luminous, high-end 3D render, centered composition with generous negative space, vertical portrait aspect ratio.