Code completion for CSS files has been added to RSTALanguageSupport. Icons were graciously borrowed from Eclipse (as usual).
You get code completion for at-rules and HTML tags for selectors:
at-rules and HTML tags
As well as property names:
Property Completions
And for certain properties, you’ll also get code completion for their values:
Value Completions
By default, the completion popup is automatically triggered (after a delay) when typing the “@” character for at-rules, and when typing ‘:’ or a space after a property name. As always, this is configurable.
Moving forward, short documentation for each CSS property (and values too!) would be awesome. If anyone has time or motivation and wants to contribute, pull requests or patches are welcome!