Sudoku Level Picker Interaction

In this onboarding level selection screen, tapping any difficulty card triggers a fluid accordion transition. The selected card expands vertically with a spring-like bounce, revealing a detailed description and a checkmark, while its background brightens. Simultaneously, the previously active card collapses back to its compact state, fading out its description. The surrounding cards smoothly shift up or down to accommodate the changing heights, creating a highly tactile and responsive selection experience.