ui4-review

name	ui4-review
description	Review UI4 CSS migrations for proper token usage. Checks that CSS variables are used instead of hardcoded values.

UI4 Review

Reviews CSS changes and auto-fixes token violations.

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Important: Palette vs Semantic Tokens

--ramp-* tokens are the raw color palette (e.g., --ramp-white-1000, --ramp-blue-500). These are used only in colors.css to define semantic tokens.

--color-* tokens are context-aware semantic tokens (e.g., --color-bg, --color-text-brand). These handle light/dark theming automatically.

Components and elements should ALWAYS use --color-* semantic tokens, never --ramp-* palette tokens directly.

/* ❌ BAD - using raw palette */
background: var(--ramp-white-1000);

/* ✅ GOOD - using semantic token */
background: var(--color-bg);

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Process

Step 1: Get Changed CSS Files

git status --porcelain | grep '\.css$'

Or if a specific file is provided, use that directly.

Step 2: Parallel Violation Detection

Run these grep searches IN PARALLEL to detect all violation types at once:

# 1. SCSS Nesting Violations (BEM patterns that don't work in CSS)
grep -n '&__\|&--' "$FILE"

# 2. Hardcoded Spacing (px/rem values that should be tokens)
grep -nE ':\s*[0-9]+px|:\s*[0-9.]+rem' "$FILE"

# 3. Hardcoded Colors (hex, rgb, rgba - includes box-shadow)
grep -nE '#[0-9a-fA-F]{3,8}|rgba?\(' "$FILE"

# 4. Legacy Theme Variables
grep -nE 'var\(--theme-|var\(--style-|var\(--base\)' "$FILE"

# 5. Old Token Names (pre-UI4 naming)
grep -nE '\-\-bg-default|\-\-bg-secondary|\-\-text-default|\-\-text-secondary|\-\-icon-default|\-\-icon-secondary|\-\-border-default|\-\-border-strong' "$FILE"

# 6. Raw Palette Usage (should use semantic tokens instead)
# Skip this check for colors.css which defines the semantic tokens
grep -nE 'var\(--ramp-' "$FILE"

Invoke all 6 grep commands in a single parallel batch, then analyze results.

Note: Raw --ramp-* violations are only flagged in component CSS files, not in colors.css where they're used to define semantic tokens.

Step 3: Auto-Fix by Priority

1. SCSS Nesting (breaks CSS entirely) — Fix first
2. Legacy Variables (deprecated) — Replace with new tokens
3. Old Token Names (pre-UI4) — Convert to --color-* naming
4. Raw Palette Usage (--ramp-* in components) — Replace with semantic --color-* tokens
5. Hardcoded Values (spacing, colors, radius) — Replace with tokens

Step 4: Report

After fixing, report:

• Total violations found
• Violations auto-fixed
• Violations that need manual review (no clear token match)

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Violation Reference

SCSS Nesting (BREAKS CSS)

Pattern	Issue	Fix
&__element	BEM element concat	Use flat .block__element selector
&--modifier	BEM modifier concat	Use flat .block--modifier selector
.child { .parent--mod & }	Parent reference	Move to .parent--mod .child

What DOES work: &:hover, &:focus, &::before, & .child

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Spacing Tokens

Value	Token
4px / 0.25rem	--spacer-1
8px / 0.5rem	--spacer-2
12px / 0.75rem	--spacer-2-5
16px / 1rem	--spacer-3
24px / 1.5rem	--spacer-4
32px / 2rem	--spacer-5
40px / 2.5rem	--spacer-6

Rounding rules — ALWAYS round to nearest token:

Pixel Range	Token	Notes
0-2px	--spacer-0	Use 0
3-6px	--spacer-1 (4px)	5-6px rounds to 4px
7-10px	--spacer-2 (8px)	10px rounds DOWN to 8px
11-14px	--spacer-2-5 (12px)	13.33px rounds to 12px
15-20px	--spacer-3 (16px)	15px, 20px both round to 16px
21-28px	--spacer-4 (24px)
29-36px	--spacer-5 (32px)	30px rounds to 32px
37-48px	--spacer-6 (40px)

Rule: For values ≤ 40px, ALWAYS use a single token (no calc()). For values > 40px, use calc() with a spacer token.

Exceptions: 0, percentages, auto, inherit, -1px (for clip offsets)

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Stroke Width Tokens

Value	Token
1px	--stroke-width-small

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Radius Tokens

Value	Token
2px / 0.125rem	--radius-small
5px / 0.3125rem	--radius-medium
13px / 0.8125rem	--radius-large
9999px	--radius-full

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Elevation Tokens (Box Shadows)

Defined in packages/ui/src/css/elevations.css.

Never use hardcoded rgba() for box-shadows. Use elevation tokens instead:

Token	Use Case
--elevation-300-tooltip	Tooltips, small floating elements
--elevation-400-menu-panel	Menus, dropdowns, floating panels
--elevation-500-modal-window	Modals, dialogs, full overlays

/* ❌ BAD - hardcoded shadow */
box-shadow: 0 -2px 16px -2px rgba(0, 0, 0, 0.2);

/* ✅ GOOD - elevation token */
box-shadow: var(--elevation-400-menu-panel);

Elevations automatically adjust for light/dark themes.

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Semantic Color Tokens (UI4 Naming)

All semantic colors use the --color- prefix. The default category and variant are implicit.

Old Name	New Name (UI4)
--bg-default	--color-bg
--bg-secondary	--color-bg-secondary
--bg-hover	--color-bg-hover
--bg-selected	--color-bg-selected
--bg-brand	--color-bg-brand
--bg-danger	--color-bg-danger
--bg-success	--color-bg-success
--bg-warning	--color-bg-warning
--text-default	--color-text
--text-secondary	--color-text-secondary
--text-tertiary	--color-text-tertiary
--text-brand	--color-text-brand
--text-danger	--color-text-danger
--text-success	--color-text-success
--icon-default	--color-icon
--icon-secondary	--color-icon-secondary
--icon-tertiary	--color-icon-tertiary
--icon-brand	--color-icon-brand
--icon-danger	--color-icon-danger
--border-default	--color-border

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Legacy Variables (Replace Immediately)

Legacy	Replacement
--theme-elevation-0	--color-bg
--theme-elevation-50	--color-bg-secondary
--theme-elevation-100	--color-border
--theme-text	--color-text
--style-radius-m	--radius-medium

var(--base) Conversion: Legacy token = 20px. Convert using:

Original	Pixels	Replacement
var(--base) * 0.4	8px	var(--spacer-2)
var(--base) * 0.5	10px	calc(var(--spacer-1) * 2.5)
var(--base) * 0.6	12px	var(--spacer-2-5)
var(--base)	20px	calc(var(--spacer-4) * 0.833)
var(--base) * 2	40px	var(--spacer-6)

See ui4 skill Step 1 for full conversion table.

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Behavior

DO NOT just report violations. FIX THEM immediately using replace_string_in_file or multi_replace_string_in_file.

When a violation has no clear token match (e.g., 3px or an unusual rem value), flag it for manual review but don't guess.

For each violation:

1. Identify the exact line and value
2. Determine the correct token replacement
3. Use replace_string_in_file to fix it immediately
4. Report what was fixed

Only flag (don't fix) when:

• No matching token exists (e.g., 18px badge size)
• Value is intentional (e.g., 1px border, 0)
• Ambiguous replacement

Empty CSS files: If a component's CSS file becomes empty after migration (all styles now handled by shared components like Button), delete the CSS file and remove its import from the component.

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Output Format

After auto-fixing, report:

## Auto-Fixed

✅ Collapsible/index.css:9 — `height: 2rem` → `height: var(--spacer-5)`
✅ Collapsible/index.css:120 — `width: 2rem` → `width: var(--spacer-5)`

## Flagged (Manual Review)

⚠️ ErrorPill/index.css:15 — `height: 1.125rem` (18px) — no matching token

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Summary

After all fixes, provide a simple summary:

File	Fixed	Flagged
Collapsible/index.css	2	1
ErrorPill/index.css	0	2