User installs extension → extension automatically injects fb.css on facebook.com pages at document_start → content script (cs.js) verifies user is logged into Facebook, then signals background script to apply theme → CSS overrides change colors, fonts, and layout to resemble the old Facebook design

Target users: Facebook users who preferred the pre-September 2020 classic layout / Users dissatisfied with Facebook's new design who want a familiar look

Extension is very small and straightforward (CSS injection + simple JS checks), so the analysis is highly deterministic
Cannot verify if the CSS overrides still work effectively with Facebook's current DOM structure
Future themes feature mentioned in options.html has no implementation to analyze

Monetization

No paid features detected

No payment platforms, billing APIs, subscription logic, upgrade prompts, or gated features found anywhere in the source code. The options.html popup mentions 'In a future update, you will be able to choose from hundreds of themes' but this is a forward-looking statement with no current implementation or monetization. The deterministic scan found zero paid keywords in actual code; the 'pro' hit was a false positive in the base64-encoded verified_contents.json.

Confidence: 95
Payment platform: --
Source: AI / High
Login required: No
Reason: The extension itself has no login system or account requirement. It operates purely as a CSS injector on facebook.com pages. While cs.js lines 13-15 check if the user is logged out of Facebook and lines 40-45 check for Facebook's c_user cookie, this is a check for the user's existing Facebook session—not a login requirement imposed by the extension. The extension reads Facebook's own DTSG token and c_user cookie only to confirm the user is logged into Facebook before applying theme changes.

Permission risk

Medium-risk permissions

This estimate uses declared permissions and host permissions to assess access scope and sensitivity.

扩展能力较强：storage

Publisher

ModernKit.one

Alesandro Ortiz Rivera

Email: [email protected]
Phone: +19292668021
Address: 44-70 21st Street #3210 Long Island, NY 11101 US

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