Build a web soundscape mixer that feels like a physical desktop console with a soft, neumorphic look. I should be able to turn on ambient tracks like Rain, Thunder, and Cafe Chatter by pressing deep, pillowy buttons that pop to a flush "on" state, and adjust each track with a smooth volume slider set into a soft trough. The UI should animate subtly, feel responsive, and reflect state instantly. Use React for the UI, mix the audio with the Web Audio API so multiple loops blend cleanly, and keep a single source of truth for which sounds are active and their volumes (Zustand is fine).