You are an expert 2nd-grade curriculum designer and elementary teacher with 15+ years experience creating Common Core-aligned materials. Your job is to create a SINGLE, reusable MASTER TEMPLATE for generating complete, ready-to-print PDF lesson packages.

Subjects covered (create one unified template that works for all three):
- Mathematics
- Phonics & Reading
- Spelling & Grammar

The final output must be a structured template (in clean Markdown + YAML frontmatter) that I can reuse in future prompts like: "Using the master template, generate a full PDF lesson on [specific topic] for [subject]."

Requirements for the template:
- Must be visually appealing and professional when converted to PDF (use simple Markdown that renders beautifully with Pandoc/WeasyPrint or similar: headings, bullet points, tables, image placeholders, colored callouts if possible).
- Age-appropriate for 7-8 year olds: short sentences, fun language, engaging activities, hands-on elements, colorful descriptions.
- Explicitly aligned to Common Core State Standards (CCSS) for Grade 2:
  • Math: 2.OA (addition/subtraction within 100, word problems), 2.NBT (place value), 2.MD (measurement/data), 2.G (geometry).
  • Phonics/Reading: RF.2.3 (phonics/word analysis – vowel teams, decoding two-syllable words), RF.2.4 (fluency), RL/RI standards.
  • Spelling/Grammar: L.2.1 (grammar/usage), L.2.2 (capitalization, punctuation, spelling patterns).
- Every generated lesson must include these exact sections in order:
  1. Header (title, subject, CCSS codes, estimated time, materials list)
  2. Learning Objectives (2-3 clear, measurable objectives in student-friendly language)
  3. Warm-Up / Hook (engaging 5-minute starter)
  4. Direct Instruction / Modeling
  5. Guided Practice (with examples)
  6. Independent Practice / Worksheet section (printable exercises)
  7. Assessment / Exit Ticket
  8. Differentiation (support for struggling students + extension for advanced)
  9. Homework / Extension (optional fun activity)
  10. Visual/Engagement Notes (describe 2-3 kid-friendly images or diagrams with exact prompts for DALL-E or placeholders)
- Include built-in quality checks: activities must be interactive, multi-sensory, culturally responsive, and include variety (games, drawing, partner work, movement).
- PDF layout rules: clean fonts (suggest sans-serif), plenty of white space, large readable text, borders/decorative elements for 2nd graders, answer key on a separate page if needed.
- Output format: First output the complete MASTER TEMPLATE definition (as a Markdown file structure with placeholders like {{TOPIC}}, {{CCSS}}, {{ACTIVITIES}} etc.). Then generate one sample lesson using the template for each subject so I can verify.

Be extremely rigorous — this template will be used to generate hundreds of lessons. Make it foolproof and educator-approved.