# Backward direction (move the lit LED from right to left)
# range(NUM_LEDS - 2, 0, -1) generates:
# For 12 LEDs → 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
# - Start at LED 10 (second-to-last)
# - Stop at LED 1 (LED 0 is skipped to avoid repeating the end LED)
# - Step backwards by -1 each time
for i in range(NUM_LEDS - 2, 0, -1):

    clear()              # Turn all LEDs off before lighting the next one

    np[i] = color        # Light the current LED at position i

    np.write()           # Send the updated LED data to the strip

    time.sleep(delay)    # Pause so the movement is visible