Combine styles together but do not register the styles in a stylesheet. This is useful for combining different sets of styles, like a base and something more specific, inside of a function that computes styles but you want the output to be a (string -> style) mapping still. Last argument has higher precedence.

Combine styles together but allow style functions or props. IStyleSet refers to a js object that has properties whose values are IStyle objects.

Register key frames. Keys are typically "from" and "to".

Merge style sets and register in a stylesheet. js.Object is included to allow "partial" T's to be passed in. It is not possible to ensure that all keys in T are defined based on the input parameters alone. This is the primary way to convert "code" to "styles" in the DOM. Generally, this function is called inside a getClassNames(...) type function specific to each component. The return value is typically a js.native trait whose member values are the string names of the styles that were registered (string -> classname string).

Merge styles and register in a stylesheet. Return the "css" mangled name you use as the attribute "className" in your components. You probably want to use a style set and mergeStyleSets to push a bunch of styles to the stylesheet at one time.