Flappy Bird clone in pygame (one shot, scoring + random pipes)

Create a complete Flappy Bird game in Python using pygame. Requirements: 1. Bird flaps upward when the player presses space or the up arrow; gravity pulls it down. 2. Randomly spaced pipes with a gap wide enough to fly through. 3. Increment the score by 1 each time the bird passes a pair of pipes without hitting them; show the score on screen. 4. Color the pipes randomly one of: dark green, light brown, or dark gray. 5. On collision or falling off screen, show "Game Over", the best score so far, and a restart prompt. Put everything in a single runnable file.