Create a modern, minimalist logo for a fitness app called GrindFit. Design a strong geometric icon representing strength and movement, such as a stylized ‘G’, abstract dumbbell, or dynamic lightning-shape symbol. Use a bold, high-contrast color palette of deep black and vivid purple (#6A0DAD–#8B2CF5). Include smooth gradients or neon-glow accents for a sleek tech-fitness look. The typography should be clean, sharp, and modern sans-serif, emphasizing power and discipline. The logo must look excellent as a mobile app icon and on dark backgrounds.”