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Contributors guide on Firefox advanced customization with CSS
What you need to know about Firefox customization with the userChrome.css file and how to help users get more help or revert their changes.
File a bug report or feature request for Mozilla products
Learn where to report a bug or file a feature request for Firefox, Thunderbird and other Mozilla products.
Contributors Guide to Writing a Good Bug
This article explains how to use Bugzilla to report and explain issues you encounter into something a Mozilla engineer can work with.
How to contribute to article localization
Learn how to translate SUMO articles in to your native language.
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