# Settings UI Design — kafka **Date:** 2026-03-22 **Status:** Approved ## Overview A lightweight preferences popover anchored to the top-right, just below the header. Triggered by a gear icon, it lets users adjust theme, enabled engines, and search defaults without leaving their current page. All changes auto-save to `localStorage` on every interaction. ## Layout & Structure - **Trigger**: Gear icon (⚙️) in the top-right header, aligned with the header's right edge - **Panel**: 280px wide, max-height 420px, scrollable internally, rounded corners, subtle shadow, anchored top-right (drops down from trigger, like a dropdown) - **Close**: × button in panel header, click outside the panel, or pressing Escape - **No Save button** — every interaction immediately writes to `localStorage` ## Interaction Flow 1. User clicks ⚙️ → panel drops down from top-right (200ms ease) 2. User toggles/clicks → changes apply instantly to DOM + write to `localStorage` 3. User clicks × or outside or Escape → panel closes, settings persist 4. **Accessibility**: Focus is trapped within the panel while open. Trigger button uses `aria-expanded` and `aria-controls`. Escape key closes the panel. ## Mid-Search Changes When opened during an active search on `results.html`: - Engine toggles update `localStorage` immediately, but **current results remain unchanged** - A subtle inline note below the engines section: *"Engine changes apply to your next search"* ## Sections ### Appearance - Three theme buttons: ☀️ Light / 🌙 Dark / 💻 System - Clicking immediately applies via `document.body.classList` + writes to localStorage - "System" reads `prefers-color-scheme` and updates on change ### Engines - 2-column grid of toggle switches for all 9 engines - Each row: engine name + toggle switch - Enabled = filled accent color; Disabled = gray outline ### Search Defaults - Safe search: dropdown (Moderate / Strict / Off) - Default format: dropdown (HTML / JSON / CSV) ## Default State ```js const DEFAULT_PREFS = { theme: "system", engines: ["wikipedia", "arxiv", "crossref", "braveapi", "qwant", "duckduckgo", "github", "reddit", "bing"], safeSearch: "moderate", format: "html" }; ``` ## Persistence ```js // Written on every interaction localStorage.setItem('kafka_prefs', JSON.stringify({ ... })); // Read on page load — merge with DEFAULT_PREFS const saved = JSON.parse(localStorage.getItem('kafka_prefs') || '{}'); const prefs = { ...DEFAULT_PREFS, ...saved }; ``` ## Responsive Behavior - **Mobile (<768px)**: Panel becomes a **bottom sheet** — 100% width, slides up from the bottom, top corners rounded, max-height 70vh. Trigger moves to a fixed bottom-right FAB button. - Panel never covers the search input ## Applied to Existing Code - `base.html` — add gear button in header, panel markup at end of `` - `kafka.css` — popover styles, toggle switch styles, bottom sheet styles for mobile - `settings.js` — localStorage read/write, theme application, panel toggle, aria attributes, focus trap