If you've never worked on large websites in old browsers, this one will be news to you.
Older versions of Internet Explorer only load a certain amount of CSS before they stop reading the rest of the file with no warning.
There are 3 limits:
@import up to 31 sheets@import nesting supports up to 4 levels deepThat was quite an exotic bug to run into at the time. It took me quite a while to figure out what was going on.