Code samples with multiple indent levels don't display correctly in Chrome and Firefox

[itsananderson]

I just noticed this on the Extending page. The code samples near the end of the page with the MyPlugin_API_MyType class are indented incorrectly. Playing around with the styles briefly, it looks like the letter-spacing: -1px rule for .content pre > code is what's causing it. Interestingly enough, it seems to display fine in IE on Windows, and Safari on OS X.