I have never used it myself, but you can try the free trial version of Skybound Stylizer . p>
Here is a quote:
CSS editing on the web
Open any site, make changes, and then save it back to the server via FTP, SFTP or a network share or others.
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The CSS real-time stylizer extends to 9 different integrated web browsers. On Windows, Google Chrome, Internet Explorer 6, 7 and 8 and Firefox 2.0, 3.0, 3.5, 3.6 are supported. Mac Safari is supported.
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Stylizer workflow cannot be easier. Just open the URL or HTML page that you want to change, the style sheets are automatically extracted from the page, and you are ready to start making changes.
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