App icon logo design for 'RingSizePro', a digital jewelry measurement tool. Central element is a sleek, metallic golden ring band viewed from top-down. Integrated into the ring design are stylized digital caliper jaws and precise ruler measurement tick marks, symbolizing accuracy. The background is a solid, deep royal navy blue (#0f172a). The art style is premium vector illustration, flat design with subtle 3D lighting gradients to show the metallic texture of the gold. Minimalist, clean lines, professional UI aesthetic, high fidelity, 8k resolution, centered composition.