theme-consistency

name: theme-consistency description: Enforce consistent theming across all prototype mockup screens. Auto-loads theme.yaml, validates CSS variable usage, prevents hardcoded values, and maintains visual consistency session-to-session. Use during /prototype create when generating new screens.

Loading and enforcing theme.yaml values during mockup generation
Preventing hardcoded colors, spacing, and typography values
Validating new screens match established patterns
Locking theme after first screen approval to ensure session-to-session consistency

This prevents the common problem where screens created in different sessions drift in style, creating an inconsistent prototype that undermines the design intent.

<quick_start> <when_to_invoke> Automatically invoke this skill when:

/prototype create [screen] is called and theme.yaml exists
Generating HTML mockup content for any screen
User requests a new prototype screen in any session

Do NOT invoke when:

Creating the very first screen (theme not yet established)
User explicitly requests to reset/modify theme </when_to_invoke>

<basic_workflow>

Load Theme - Read design/prototype/theme.yaml
Check Lock Status - If locked: true, enforce; if false, may update
Load Context - Get app_type, core_goal, layout, tone, density
Generate Screen - Create HTML using theme CSS variables
Validate - Check for hardcoded values, fix violations </basic_workflow>

<key_rules> NEVER use:

Hardcoded hex colors: #3b82f6, #ffffff
Hardcoded RGB: rgb(59, 130, 246)
Hardcoded spacing: padding: 17px, margin: 32px
Arbitrary values: text-[15px], p-[23px]

ALWAYS use:

Theme CSS variables: var(--color-primary), var(--space-4)
Shared component classes: .btn--primary, .card, .form-input
Density classes: .density-compact, .density-spacious </key_rules> </quick_start>

<detailed_procedures> <theme_loading>

Loading Theme Configuration

When generating any prototype screen, FIRST load the theme:

# Read design/prototype/theme.yaml
theme:
  locked: true|false
  palette:
    primary: "oklch(55% 0.2 250)"
    # ... all colors
  typography:
    heading_font: "Inter, system-ui, sans-serif"
    # ... font settings
  spacing:
    unit: "8px"
    # ... spacing scale
  tone:
    style: "professional"  # affects content voice
    density: "comfortable" # affects spacing multipliers

Lock Status Behavior

If locked: true:

Theme is immutable
All new screens MUST use existing theme values
Warn if user requests theme changes
Suggest creating new prototype instead

If locked: false:

First screen is being created
Theme values may be refined based on user feedback
After user approves first mockup, set locked: true </theme_loading>

<screen_generation>

Generating Consistent Screens

HTML Structure

Every screen MUST follow base.html structure:

<!DOCTYPE html>
<html lang="en">
<head>
  <title>{{SCREEN_TITLE}} - {{APP_NAME}}</title>
  <link rel="stylesheet" href="../../theme.css">
  <link rel="stylesheet" href="../../shared.css">
  <style>/* Screen-specific overrides only */</style>
</head>
<body class="theme-{{TONE_STYLE}} density-{{DENSITY}}">
  <a href="#main-content" class="skip-link">Skip to main content</a>

  <!-- Navigation (if applicable) -->
  <nav class="nav nav--{{LAYOUT}}">...</nav>

  <!-- Main Content -->
  <main id="main-content" class="main main--{{LAYOUT}}">
    {{SCREEN_CONTENT}}
  </main>
</body>
</html>

CSS Variable Usage

Element	Correct	Incorrect
Button background	`var(--color-primary)`	`#3b82f6`
Card padding	`var(--space-4)`	`32px`
Heading size	`var(--text-2xl)`	`1.953rem`
Border radius	`var(--radius-md)`	`8px`
Box shadow	`var(--shadow-md)`	`0 4px 6px rgba(...)`
Transition	`var(--transition-base)`	`150ms ease`

Component Reuse

Use shared.css classes instead of inline styles:

<!-- CORRECT -->
<button class="btn btn--primary">Submit</button>
<div class="card card--elevated">...</div>
<input class="form-input" type="text">

<!-- INCORRECT -->
<button style="background: #3b82f6; padding: 8px 16px;">Submit</button>
<div style="background: white; box-shadow: 0 4px 6px rgba(0,0,0,0.1);">...</div>

</screen_generation>

After generating screen HTML, validate:

1. No Hardcoded Colors

# Check for hex colors
grep -E "#[0-9a-fA-F]{3,6}" screen.html

# Check for rgb/rgba
grep -E "rgb\(|rgba\(" screen.html

# Check for hsl/hsla
grep -E "hsl\(|hsla\(" screen.html

2. No Hardcoded Spacing

# Check for pixel values not in variables
grep -E "padding:\s*\d+px" screen.html
grep -E "margin:\s*\d+px" screen.html
grep -E "gap:\s*\d+px" screen.html

3. Font Usage

# Check for hardcoded font-family
grep -E "font-family:\s*[^v]" screen.html  # Should use var()

4. Theme Variable Coverage

Ensure all visual properties use theme variables:

Colors: var(--color-*)
Spacing: var(--space-*)
Typography: var(--text-*), var(--font-*)
Effects: var(--shadow-*), var(--radius-*)

<content_presentation>

Content Presentation by Screen Type

Use context from theme.yaml to guide content structure:

Entry/Auth Screens

Single focus, minimal distraction
Centered card layout
Clear primary CTA
Minimal navigation

Dashboard/Overview Screens

Scannable grid layout
Summary cards with key metrics
Quick action shortcuts
Navigation hub role

Create/Edit Screens

Form-focused layout
Progressive disclosure if complex
Clear validation feedback
Save/Cancel actions visible

Browse/List Screens

Table or card grid
Search/filter bar at top
Pagination or infinite scroll
Quick actions per item

Detail/View Screens

Hero section with primary info
Tabbed or sectioned content
Action buttons in header
Related items/navigation </content_presentation> </detailed_procedures>

<validation_output>

Validation Report Format

After screen generation, output validation status:

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
THEME CONSISTENCY CHECK
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Screen: dashboard-overview.html
Theme: [APP_NAME] Theme (locked)

CHECKLIST:
✅ Uses theme.css variables
✅ Imports shared.css
✅ No hardcoded colors
✅ No hardcoded spacing
✅ Uses shared component classes
✅ Follows base.html structure
✅ Includes skip link
✅ Matches layout pattern (sidebar)
✅ Applies density setting (comfortable)

STATUS: PASS
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

If violations found:

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
THEME CONSISTENCY CHECK
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Screen: settings-form.html
Theme: [APP_NAME] Theme (locked)

VIOLATIONS FOUND:

Line 45: Hardcoded color
  Before: background: #f3f4f6;
  After:  background: var(--color-neutral-100);

Line 67: Hardcoded spacing
  Before: padding: 24px;
  After:  padding: var(--space-3);

Line 89: Missing shared class
  Before: <button style="...">
  After:  <button class="btn btn--primary">

STATUS: FAIL (3 violations)
Auto-fixing violations...
STATUS: PASS (after fixes)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

</validation_output>

Theme Template: .spec-flow/templates/prototype/theme.yaml
CSS Variables: .spec-flow/templates/prototype/theme.css
Base HTML: .spec-flow/templates/prototype/base.html
Shared Styles: .spec-flow/templates/prototype/shared.css
Design Tokens: docs/project/style-guide.md

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