A basic Chrome extension framework (Manifest V3).

• manifest.json – Extension config (name, version, permissions, popup, background)
• popup.html / popup.css / popup.js – UI when you click the extension icon
• background.js – Service worker (runs in background, survives when popup is closed)

1. Open chrome://extensions
2. Turn on Developer mode
3. Click Load unpacked
4. Select this folder

Add PNGs to an icons/ folder and reference them in manifest.json:

• icons/icon16.png (16×16)
• icons/icon48.png (48×48)
• icons/icon128.png (128×128)

Then add under "action" and at top level:

"default_icon": { "16": "icons/icon16.png", "48": "icons/icon48.png", "128": "icons/icon128.png" },
"icons": { "16": "icons/icon16.png", "48": "icons/icon48.png", "128": "icons/icon128.png" }

• Content scripts: inject JS/CSS into web pages (add "content_scripts" in manifest)
• Permissions: e.g. "activeTab", "storage", "tabs" for more capabilities
• Options page: add "options_page": "options.html" or "options_ui" for settings