Act as a professional logo designer with 10+ years of experience in tech branding. Design a sleek, modern logo for an AI assistant app named [APP_NAME]. The logo should embody [KEY_THEME] (e.g., intelligence, speed, or friendliness) using a color palette of [COLOR_SCHEME]. Incorporate subtle tech elements like circuits or abstract neural networks while maintaining minimalism. The design must be scalable, recognizable at small sizes, and work in both light/dark modes. Avoid clichés like robots or chat bubbles—focus on unique symbolism. Deliver 3 style variations: flat, gradient, and isometric. Include a 1-sentence rationale for each design choice.