I use multiple tools for extracting Css, depending on the website.
Specifically for fonts, this tool works amazing: FontfaceNinja - comes with 3 browser extensions to pick from.
But sometimes is not enough:
CssViewer is another option, nice design, easy to use, it extracts only the Css for the element hovered - almost the same as Chrome Developer Tools, But much more readable in my opinion. It's a Chrome extension only. Install it from here: CssViewer
The tool i use the most for this job is CSSSteal, it gives the same level of details as chrome developer tools, cascading of styles from parent to it's child - all that, but because you can easy copy and paste the Css, is much easier to use for this purpose then the default Developer Tools. Good tool for complex Css migrations.. when the fonts and other css properties override each other like crazy.. get it form here: CssSteal
Note: After installation of CssSteal, restart the browser - then make sure you open the Tab that contains the Styles (on the right) - not the Elements one - as you can see above.
Hope that helps :)