I'm concerned about what level feature detections occurs. For example, it makes sense to have a native @support CSS rule checking for things like border-box su

I'm concerned about what level feature detections occurs. For example, it makes sense to have a native @support CSS rule checking for things like border-box support. But what about detecting features that are separate from rendering? Should @support check for geolocation? If not, where does that test live - javascript (modernizr, yepnope)? Is separating tests based on type of feature a good thing? If so, how should the interactions between display and feature be intelligently managed? If not, is CSS, Javascript, or some other layer the appropriate place to consolidate tests? Testing for non-rendering concerns in CSS doesn't make any sense to me, and I'm afraid our future will be HTML markup full of classes namespaced by concern, managed by javascript & feature detection. It's an evolution, but hardly elegant. (class="js-toggle function-geolocation structure-list typography-chrome")