I'm surprised nobody has mentioned inuit css[0]. It's written by the highly knowledgeable Harry Roberts (aka CSS Wizardry) and it has exactly this goal. All you get is some boiler plate stuff. It's well designed (from a code perspective) and states "inuit.css provides little-to-no design which means no undoing things, no deleting CSS and no adhering to other peoples’ design decisions.". Though I guess it might be one step back from what you want, as you won't really find widgets, carousels or anything beyond very simple components in the framework.

[0] http://inuitcss.com/