- Extract shared CSS (sidebar, theme vars, layout) into shared.css
- Extract shared JS (tailwind config, sidebar injection, theme toggle) into shared.js
- Remove ~1200 lines of duplicated code across 13 HTML pages
- Standardize all titles to format: Tool Name — WA Dev Tools
- Standardize page headers (h1 + description) across all tools
- Standardize container padding (tool-container class)
- Sidebar now injected via JS — single source of truth
- Use CSS variables for accent colors everywhere (no more hardcoded #0054e6)
