I am using ASP.NET MVC to develop a site. The CSS file has grown to 88KB and is having a little more 5,000 lines. I noticed recently that styles added at the end are not the
Theoretically, there isn't a limit.
Practically, most normal browsers (FF, Chrome, Opera, Safari) can handle whatever you throw at them. Some of the older and/or mobile browsers however (Access NetFront, for one - bundled with many mobile phones) run into problems with largish pages (about 100KB and above) and throw all kinds of errors.
TL;DR: No, unless you're trying to support all kinds of weird browsers.