Here is a complete, single-file HTML application for a 3x3 Rubik's Cube solver. It includes an intuitive visual color picker, an unfolded 2D cube layout with locked center pieces (to prevent illegal orientations), live color counters, and uses a Kociemba-based solver engine to find the shortest possible solution moves. Save the code below as an `.html` file (e.g., `cube_solver.html`) and open it in any web browser. ```html