---
id: 23
title: "Theming: Toggle button and localStorage persistence"
assignee: claude
tags: [theming, ui]
created: 2025-02-10
completed: 2025-02-10
---

## Description
Add a theme toggle control to the header that switches between dark and light mode. Persist the user's choice in localStorage so it survives page reloads. Default to dark mode when no preference is stored.

## Acceptance Criteria
- [ ] Toggle button in header-right area (sun/moon icon or similar minimal indicator)
- [ ] Clicking toggle sets `data-theme` attribute on `<html>` and saves to localStorage
- [ ] On page load, apply saved theme from localStorage before first paint (no flash of wrong theme)
- [ ] Respect `prefers-color-scheme` media query as initial default when no localStorage value exists
- [ ] Keyboard shortcut `T` toggles theme (when no modal is open)
- [ ] Toggle is visible and functional on all views (board, prompts, documents)

## Notes
