Celestial Galaxy Whale Shark

Create a single-subject digital illustration of a celestial whale shark, isolated on a clean white background. The whale shark is shown in a graceful vertical arc, swimming upward toward the upper left with its head large and rounded, mouth slightly open, tiny calm eye, broad body curving down and around into a sweeping crescent shape, and tail at the lower left. Include exactly 7 visible fins: 1 large dorsal fin on the upper back, 1 smaller rear dorsal fin, 2 side pectoral fins, 2 small lower pelvic/anal fins along the underside, and 1 broad crescent tail fin. Give the animal a smooth semi-realistic 3D painterly form with soft shading and glossy skin, but replace natural whale-shark markings with a vivid galaxy texture: saturated cobalt blue, violet, magenta, cyan, and warm pink-orange nebula gradients, filled with countless tiny star speckles and bright starbursts across the entire body. The head should glow warmer pink and peach near the snout and transition into blue and purple along the body, with turquoise highlights on the belly curve. Keep the silhouette elegant, whimsical, and serene, with no water, no bubbles, no scenery, and no decorative symbols outside the body. Add a small artist signature and date in the bottom-right corner reading {argument name="date text" default="July 30, 2026"} above {argument name="signature text" default="Oyagi"}, in subtle black handwritten script. High-resolution square-to-portrait composition, soft luminous fantasy art, crisp edges, centered subject, ample white negative space.