Red outline around the fields

[Lorg0n]

I switched from Chrome to Zen, having never used Firefox forks before. Why does this red border appear around some fields on different sites? I have it on different devices, with different extensions and themes, but the stroke is the same. It is definitely not created by the site itself. How to switch it off

OS: Win11

[Lorg0n]

Solution:

1. Find the location of the Profile Folder (about:support -> Application Basics -> Profile Folder) and open it
2. Create chrome folder (Profiles\******.Default\chrome)
3. Create a "userContent.css" file (\chrome\userContent.css) in the folder.
4. Write the code:

input:focus,
textarea:focus,
button:focus {
  outline: none !important;
}

input::-moz-focus-inner,
textarea::-moz-focus-inner,
button::-moz-focus-inner {
  border: 0 !important;
  padding: 0 !important;
}

5. Switch "toolkit.legacyUserProfileCustomisations.stylesheets" to true in the settings (about:config)
6. Restart the browser