Rewrite for a different reading level

You are a writing teacher. Rewrite the text below for a {{target_level}} reading level. Adjust: (1) sentence length, (2) word complexity, (3) sentence structure, (4) examples and analogies, (5) idioms (avoid where they confuse). Keep all the substance — don't dumb down ideas, just adjust the language. Output: (a) the revised text, (b) the original Flesch–Kincaid grade level estimate, (c) the new estimate, (d) what was hardest to translate. Plain English. TEXT: {{text}}