# Managed by IssueSpec. Hand edits are welcome; keep the schema valid. id: 13 title: Themes light and dark state: closed author: name: k33g email: ph.charriere@gmail.com createdAt: 2026-09-17T22:15:20.392Z updatedAt: 2026-09-17T23:20:00.000Z labels: [] body: | Let the user choose between a light and a dark theme, light by default. Implemented (2026-09-17): - `ui/src/theme.ts`: zustand store (`theme`: light | dark), `setTheme` / `toggleTheme` / `resetTheme`, `isTheme` guard; remembered in localStorage `ori.theme`; stamps `data-theme` on `` at module load (before the first render) and on every change. - `app.css`: the dark palette moved from `@media (prefers-color-scheme: dark)` to `:root[data-theme="dark"]`; `color-scheme` follows. The OS preference is no longer followed (user's decision: two themes only, light default). - Header button ☾ / ☀ (`aria-label` "Switch to dark/light theme") in `App.tsx`; `MonacoViewer` picks `vs-dark` / `light` from the store; the terminal stays dark. - Tests: +6 store, +1 App (124 vitest total). Quality gate PASS (run #16). - Docs: how-to `switch-the-theme` (EN + FR), architecture explanation, indexes, README. tasks: [] comments: []