Thinking about software theming and the distinction between style themes (how the UI looks) and structural themes (how the UI is arranged and organized), how these are really two separate things from each other, and how recognizing that separation may allow for designing a theming system that can apply a custom theme across arbitrary applications of arbitrary purpose
I guess I should define the context a bit more: I'm trying to solve the 'holy grail' of theming, namely "how do you simultaneously allow applications to design custom controls that work best for their usecase, while also allowing end users to personalize their whole system in a genuinely expressive (and mostly consistent) way, that can be shared between people?"