# Checklist: Frontend UI & i18n Requirements Quality

**Purpose**: Validate the quality, clarity, and completeness of the requirements for the unified frontend CSS and localization feature.

**Meta**:
- **Feature**: 013-unify-frontend-css
- **Created**: 2026-01-23
- **Focus**: UX Consistency, Component Contracts, i18n Completeness

## Requirement Completeness
- [x] CHK001 Are all necessary UI components (Button, Input, Select, Card, PageHeader) explicitly identified for standardization? [Completeness, Spec §FR-002]
- [x] CHK002 Are the supported languages (RU, EN) and default language (RU) explicitly defined? [Completeness, Spec §FR-008, §FR-009]
- [x] CHK003 Is the persistence mechanism for language selection (LocalStorage) specified? [Completeness, Spec §FR-010]
- [x] CHK004 Are the specific pages (Dashboard, Settings) targeted for migration identified? [Completeness, Spec §FR-005]

## Requirement Clarity
- [x] CHK005 Is the "consistent spacing" requirement quantified with specific values or a system (e.g., Tailwind scale)? [Clarity, Spec §FR-004]
- [x] CHK006 Are the specific visual properties (color, padding, hover state) that must be consistent defined in the design system configuration? [Clarity, Spec §SC-001]
- [x] CHK007 Is the behavior of "legacy components" clearly defined (refactor vs. approximate)? [Clarity, Spec Edge Cases]

## Requirement Consistency
- [x] CHK008 Do the component contracts in `contracts/ui-components.md` align with the visual requirements in the spec? [Consistency]
- [x] CHK009 Is the decision to use Svelte stores for i18n consistent with the requirement for client-side persistence? [Consistency, Research §2]

## Acceptance Criteria Quality
- [x] CHK010 Can the "consistent visual experience" be objectively verified through the defined independent tests? [Measurability, Spec §User Story 1]
- [x] CHK011 Is the "0 instances of arbitrary hardcoded color values" criterion measurable via static analysis or search? [Measurability, Spec §SC-003]
- [x] CHK012 Is the language persistence requirement testable by reloading the page? [Measurability, Spec §SC-006]

## Scenario Coverage
- [x] CHK013 Are requirements defined for the scenario where a translation key is missing? [Coverage, Spec Edge Cases]
- [x] CHK014 Are requirements defined for the initial load state (default language)? [Coverage, Spec §User Story 3]
- [x] CHK015 Are requirements defined for switching languages while on a page with dynamic content? [Coverage, Gap]

## Edge Case Coverage
- [x] CHK016 Is the behavior defined for text that overflows when translated to a longer language (e.g., RU vs EN)? [Edge Case, Gap]
- [x] CHK017 Is the behavior defined if LocalStorage is disabled or inaccessible? [Edge Case, Gap]
- [x] CHK018 Are requirements defined for responsive behavior on mobile devices? [Edge Case, Spec §Edge Cases]

## Non-Functional Requirements
- [x] CHK019 Are there specific performance targets for language switching (e.g., "instant", "no layout shift")? [NFR, Research §Technical Context]
- [x] CHK020 Are accessibility requirements (ARIA labels, keyboard nav) defined for the new components? [NFR, Gap]