How to override the CSS of a site in Firefox with userContent.css?

Question

In Mozilla Firefox, I want to create userContent.css which overrides the CSS of a site, say this one.

Where should I create the file? Could you please describe it based on Windows 7?

Answer 1

Step 1 : Open Firefox, Go to 'Firefox' menu at the top-left of the browser.

Firefox --> Help --> Troubleshooting Information --> Open Containing Folder

Step 2 : Create a folder named chrome

Step 3 : Create a css file userContent.css

Step 4 : Copy the following code to the files userContent.css

Step 5 : @-moz-document domain(your_domain.com) { img { opacity: 0.05 !important; } }

Step 6 : Replace your_domain.com with specified domain name, say superuser.com if we need to format the images in superuser.com

Step 7 : Resatrt user browser

Step 8 : Wow... You are great.