Please generate a simpler Zen mandala design that is smaller in size, ensuring it stays fully centered on an 8.5 x 11 inches page with a clear margin of at least two centimeters on every side. The design should have fewer details to emphasize clarity and ease of coloring. Ensure the background of the image is completely white, eliminating any cream or off-white shades. The mandala should offer a clear, meditative space with bold, clean lines suitable for coloring and meditation. Aim for high-resolution, monochromatic line art that promotes focus and tranquility.