Custom CSS for a 3rd-party site

Question

Is it possible to apply a custom user CSS over a specific site? Say I created a custom CSS file that I wanted to use while browsing the google.com domain, how would I apply it / add it?

I would like to know for Firefox and IE if its possible.

Answer 1

The Stylish extension for Firefox allows this. I don't know if there's a similar capability in IE.

Answer 2

If you read into userscripts this is entirely possible using a bit of JavaScript to inject say a reset css file and then your custom css to websites you define.

Answer 3

There is a few extensions for Firefox that let you manage user styles, try for example this one.

Most other browsers have a custom stylesheet preference somewhere in their preferences. However when you use that it will apply to all sites you browse, so be careful what modifications you use. However some sites (a good example is facebook) have so arcane classes on their body tags that it is easy to create styles that although applied globally will affect only the site you need to.