This is only useful for Firefox, and probably you've figured something else out already, but just in case; there's a LJ tool on the mozilla site, under Add-ons > Browse > Extensions > Social & Communication. As I type this, it's at the top of the page here:

https://addons.mozilla.org/en-US/firefox/browse/type:1/cat:71

I only use the style mine and thread unfolder, but they both work very well.