Vanilla Web (HTML/CSS/JS)

Baseline constraints (from the rule)

Use these as non-negotiables:

• "HTML/CSS/JS only (no framework)."
• "Keep JS modular (ESM), split responsibilities (SRP)."
• "Prefer small, focused functions and pure utilities; avoid global state."
• "Ship complete runnable files and minimal tests before marking done."

When to activate this skill

Activate when the user asks for:

• vanilla JS / plain HTML/CSS/JS / static page
• “no framework”, “no React/Vue/Angular”
• small UI components (modal, tabs, dropdown, form validation) built directly in the DOM
• refactors to remove framework dependencies or reduce JS complexity