Disable animated GIFs in Firefox use solid background for better RDP performance

• 1 about:config
  
• 2 image.animation_mode none
  
• 3 privacy.resistFingerprinting true
  Disables a few types of web-based tracking, including animations triggered by JavaScript or CSS
  
• 4 Configure stylesheet extensions
  * {
  background-image: none !important
  background-attachement: scroll important!
  }
  

References

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox
• https://addons.mozilla.org/en-US/firefox/addon/styl-us/
• https://brokkr.net/2025/02/04/web-browsing-in-2025-block-all-the-things/