email-template-builder {Frontend} (v1.0)

"Ship pixels that perform, accessible by default."

Purpose

Responsive HTML email templates. Table-based layout, inline CSS, 600px max-width. Firebase Extensions trigger. [EXPLICIT] When to use: Frontend development within the Firebase/Google/Hostinger stack.

Core Principles

1. Law of Semantics: HTML first, CSS second, JS third. Semantic markup is non-negotiable. [EXPLICIT]
2. Law of Performance: Lighthouse > 90. Lazy load images. Code-split routes. Critical CSS inline. [EXPLICIT]
3. Law of Accessibility: WCAG 2.1 AA minimum. Keyboard navigable. Screen reader tested. ARIA where needed. [EXPLICIT]

Core Process

Phase 1: Structure

1. Define page/component structure with semantic HTML5. [EXPLICIT]
2. Apply design tokens from .agent/.shared/design-tokens.md. [EXPLICIT]
3. Configure responsive breakpoints (mobile-first). [EXPLICIT]

Phase 2: Build

1. Implement with framework (React/Angular) or vanilla HTML/CSS/JS. [EXPLICIT]
2. Integrate Firebase services (Auth, Firestore listeners, Storage). [EXPLICIT]
3. Add loading/error states for async operations. [EXPLICIT]

Phase 3: Validate

1. Run Lighthouse audit (> 90 on all categories). [EXPLICIT]
2. Run accessibility audit (axe-core). [EXPLICIT]
3. Test on mobile, tablet, desktop breakpoints. [EXPLICIT]

3. Inputs / Outputs

Input	Type	Required	Description
Requirements/spec	Text/File	Yes	What to build
Output	Type	Description
--------	------	-------------
Source files	HTML/CSS/JS/TSX	Production-ready code

Validation Gate

• Semantic HTML5 structure
• Responsive on all breakpoints
• Lighthouse > 90
• WCAG 2.1 AA compliant
• Firebase integration working

5. Self-Correction Triggers

[!WARNING] IF using div soup without semantic elements THEN refactor to semantic HTML5. IF Lighthouse < 90 THEN optimize before shipping.

Usage

Example invocations:

• "/email-template-builder" — Run the full email template builder workflow
• "email template builder on this project" — Apply to current context

Assumptions & Limits

• Assumes access to project artifacts (code, docs, configs) [EXPLICIT]
• Requires English-language output unless otherwise specified [EXPLICIT]
• Does not replace domain expert judgment for final decisions [EXPLICIT]

Edge Cases

Scenario	Handling
Empty or minimal input	Request clarification before proceeding
Conflicting requirements	Flag conflicts explicitly, propose resolution
Out-of-scope request	Redirect to appropriate skill or escalate