Examine source code of 9gag Night Mode

{
  "description": "Night mode for the 9gag website!",
  "manifest_version": 2,
  "name": "9gag Night Mode",
  "version": "1.1resigned1",
  "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/borderify",
  "icons": {
    "128": "9gagext.png"
  },
  "content_scripts": [
    {
      "css": [
        "9gag-override.css"
      ],
      "matches": [
        "http://9gag.com/*",
        "https://9gag.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{76ff949c-6d62-4461-8417-95996bc3ad48}"
    }
  }
}