A state is a set of conditions paired with an expression, separated by :.

@Selected: 2                    // conditions = {"Selected"}
                                // expression -> value -> number = 2

@Narrow&Mobile: "Column"        // conditions = {"Narrow","Mobile"}
                                // expression -> value -> string = "Column"

@Debug&Desktop: false           // conditions = {"Debug","Desktop"}
                                // expression -> value -> bool = false

@Alert: Red                     // conditions = {"Alert"}
                                // expression -> reference = {
                                //     item = "Red" }