"A sophisticated and cohesive abstract tattoo design on a realistic forearm in natural skin tone, featuring a cosmic time theme. The design should include bold, thick black and grey elements arranged in a balanced and harmonious manner. The composition should feature large concentric circles and spirals that flow smoothly across the forearm, integrating seamlessly with geometric patterns like triangles, hexagons, and stars. Ensure the design has a clean, unified look with minimal visual clutter. The abstract sun and moon should be incorporated in a way that complements the overall theme, with fluid shading blending naturally into the surrounding patterns. The tattoo should present a cohesive and elegant appearance, using black and grey ink to create a visually striking effect on the natural skin tone of the forearm."