---
phase: 01-design-token-foundation
plan: 01
subsystem: frontend/design-tokens
tags: [css-variables, oklch, tailwind, palette, vitest, tdd]
dependency_graph:
  requires: []
  provides:
    - pastel oklch CSS variable system in index.css
    - palette.ts typed category color module
    - vitest test infrastructure
  affects:
    - frontend/src/index.css
    - frontend/src/lib/palette.ts
    - All future component visual work in Plan 02
tech_stack:
  added:
    - vitest@4.0.18
    - "@testing-library/react@16.3.2"
    - "@testing-library/jest-dom@6.9.1"
    - "@testing-library/user-event@14.6.1"
    - jsdom@28.1.0
  patterns:
    - oklch pastel color tokens with non-zero chroma in :root
    - Single-source-of-truth palette module with typed exports
    - TDD with vitest globals and jsdom environment
key_files:
  created:
    - frontend/src/lib/palette.ts
    - frontend/src/lib/palette.test.ts
    - frontend/src/test-setup.ts
  modified:
    - frontend/src/index.css
    - frontend/vite.config.ts
    - frontend/package.json
decisions:
  - "oklch pastel tokens replace all zero-chroma neutrals in :root (--card and --popover remain pure white as locked)"
  - "--success (oklch 0.55 0.15 145) and --warning (oklch 0.70 0.14 75) semantic tokens added to :root and registered in @theme inline"
  - "--chart-1 through --chart-5 values synced with palette.ts base colors for bill, variable_expense, debt, saving, investment categories"
  - "palette.ts exports amountColorClass() with isIncome/isAvailable path (positive=text-success, negative=text-destructive) and expense path (over-budget=text-warning)"
metrics:
  duration: "~4 minutes"
  completed_date: "2026-03-11"
  tasks_completed: 3
  files_created: 3
  files_modified: 3
---

# Phase 1 Plan 01: Design Token Foundation Summary

Pastel oklch CSS variable system and palette.ts module established as the foundation layer for all subsequent visual work, with vitest test infrastructure installed and 20 unit tests passing.

## Tasks Completed

| Task | Name | Commit | Files |
|------|------|--------|-------|
| 1 | Install test infrastructure and set up vitest | cbf3552 | frontend/package.json, frontend/vite.config.ts, frontend/src/test-setup.ts |
| 2 | Replace CSS tokens with pastel oklch values and add success/warning tokens | 3f97d07 | frontend/src/index.css |
| 3 | Create palette.ts and palette.test.ts (TDD) | d5fc10d (RED), 6859b30 (GREEN) | frontend/src/lib/palette.ts, frontend/src/lib/palette.test.ts |

## What Was Built

**Pastel CSS variable system (`frontend/src/index.css`):**
- All `:root` tokens now use oklch values with non-zero chroma (lavender tint, hue ~280-290) except for the intentionally pure-white `--card` and `--popover`
- `--chart-1` through `--chart-5` mapped to category base colors (bill=blue 250, variable_expense=amber 85, debt=rose 15, saving=violet 280, investment=pink 320)
- New `--success` (green 145) and `--warning` (amber 75) semantic tokens in `:root`
- `--color-success` and `--color-warning` registered in `@theme inline` enabling Tailwind utilities `text-success`, `text-warning`

**Typed palette module (`frontend/src/lib/palette.ts`):**
- `CategoryType` union: income | bill | variable_expense | debt | saving | investment | carryover
- `CategoryShades` interface with light/medium/base oklch strings
- `palette` Record — single source of truth, base colors match CSS chart tokens
- `headerGradient(type)` — returns `React.CSSProperties` with `linear-gradient(to right, light, medium)`
- `overviewHeaderGradient()` — multi-stop gradient (carryover.light → saving.light → income.light)
- `amountColorClass(opts)` — returns `text-success`/`text-warning`/`text-destructive`/`''` per locked rules

**Test infrastructure:**
- vitest 4.0.18 with jsdom environment and globals
- `test-setup.ts` imports `@testing-library/jest-dom` matchers
- 20 unit tests covering all exports and edge cases — all passing

## Decisions Made

1. `--card` and `--popover` intentionally remain `oklch(1 0 0)` (pure white) per locked design decision — cards float visually on the tinted background
2. `--success-foreground` and `--warning-foreground` use near-white `oklch(0.99 0 0)` — neutral foreground on colored semantic backgrounds is correct and intentional
3. Sidebar tokens use slightly deeper lavender (hue 280, chroma 0.01-0.02) vs background (hue 290, chroma 0.005) for subtle visual distinction
4. `overviewHeaderGradient()` uses carryover/saving/income lights (sky→lavender→green) for the FinancialOverview header identity

## Deviations from Plan

None - plan executed exactly as written.

## Self-Check

### Files Exist

- frontend/src/lib/palette.ts: FOUND
- frontend/src/lib/palette.test.ts: FOUND
- frontend/src/test-setup.ts: FOUND
- frontend/src/index.css: FOUND (modified)

### Commits Exist

- cbf3552 (Task 1): FOUND
- 3f97d07 (Task 2): FOUND
- d5fc10d (Task 3 RED): FOUND
- 6859b30 (Task 3 GREEN): FOUND

## Self-Check: PASSED