How many levels of nested @import are allowed?

The question's all in the title really, but here's the context.

I was writing a Perl script to fetch the CSS from pages and calculate
the size of the images referenced in it.

Then I remembered that you can nest another @import statement inside
an imported or linked style sheet.

How many times can you do this? A third one inside the second one? A
fourth inside the third?

Hostile17 wrote:

Then I remembered that you can nest another @import statement inside
an imported or linked style sheet.

How many times can you do this? A third one inside the second one? A
fourth inside the third?

Until the browser with the weakest support breaks.

--
Mark.