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A rectangle in the top-left of the browser

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I'm trying to make my own userChrome.css, and after doing *{color: ...; background-color: ...;} I have an annoying non-transparent rectangle at the top-left of the browser! How can i remove this, and furthermore, where can i find the names of the browser elements like "tab", "ulr-bar" and "titlebar"? Is there a tool which i can use to find those easily?

Pic of the rectangle https://imgur.com/a/GWeFh

I'm trying to make my own userChrome.css, and after doing *{color: ...; background-color: ...;} I have an annoying non-transparent rectangle at the top-left of the browser! How can i remove this, and furthermore, where can i find the names of the browser elements like "tab", "ulr-bar" and "titlebar"? Is there a tool which i can use to find those easily? Pic of the rectangle https://imgur.com/a/GWeFh

All Replies (1)

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Generally speaking, you should not use the * selector, since that is meant to apply to every single element and you'll nearly always want to do something more specific.

As there are not a lot of Nightly users here, you might consider starting a thread on this subreddit:

https://www.reddit.com/r/FirefoxCSS/