Referencing other stylesheet files in your .CSS or .LESS source files in Visual Studio 2013

If you are building larger web application with Visual Studio and ASP.NET, you might wish to reference styles from other files to make multiple smaller style files instead of a single, large file. This feature is especially useful in .LESS files, but is helpful in plain .CSS files as well.

Normally, Visual Studio 2013 doesn't support LESS language's @import statement, but luckily, you can solve the issue by adding special reference comments. These comments start with the familiar three forward slashes like this:

/// <reference path="bootstrap.less" />

This is exactly the same type of comment that allows you to reference other JavaScript files, or TypeScript definition files from your .TS files.

I noticed that Microsoft has also blogged about this feature here. Looks like it's an undocumented feature. :-)