Regions in CSS like C# regions?

You can use this for regions...works well to make collapsible regions

/*#region RegionName*/

/*#endregion RegionName*/

The RegionName is optional in endregion, you can also use

/*#region RegionName*/

/*#endregion */

You can't do regions, but you can always just use spacing and comments to add some organization if you like.

/*Layout rules*/
body{}
div{}
etc{}

/*Typography Rules*/
etc{}

etc...

No there is no support for regions in CSS.

The usual approach is separating into different CSS files and then use a CSS minification tool for production releases that combines and minifies your CSS, i.e. see minify or YUI Compressor.