Workbook & Practice-Book Cover Collection Generator

Design a printable workbook / practice-book COVER, 3:4 portrait aspect ratio, output size 1200x1600. FIXED LAYOUT (must match across every variant of this template): a top title band occupying about the top 18% of the frame containing the subject-name title and a small grade-level ribbon badge in the top-right corner; a large center illustration zone (about the middle 55% of the frame) containing exactly one large flat-vector subject motif illustration relevant to the subject; a thin colored border frame around the entire cover; a bottom footer bar (about the bottom 12%) with a small left-aligned series/brand wordmark. Clean flat-vector illustration style, no photorealism, consistent with a children's educational worksheet/flashcard visual language. VARIABLE CONTENT for this specific example: subject name = "{subject_name}", grade level badge text = "{grade_level}", series/brand footer text = "{series_brand}", accent color = {accent_color}, center subject illustration = {subject_motif}. Render the subject name and grade-level badge as real, legible, correctly spelled text exactly as given -- do not add any other text. Do not add a watermark. Do not crop the illustration at the frame edges.