90s buttons came with their own design language: - popped-out button: available to press - popped-out but greyed out - usable, but disabled in the current con

90s buttons came with their own design language: - popped-out button: available to press - popped-out but greyed out - usable, but disabled in the current context - popped-in - currently has the mouse button depressed on it, but will not fire until you let go. in case of the taskbar, the current selected application (radio button) - flat/not 3D - not an interactive element, likely just a label Far beyond being skeumorphic in appearance, they also had a unique visual language that communicated the state of a control. The modern flat UI interfaces entirely gave up on this, and created a simplified experience that also glosses over many UX affordances that people would subconsciously pick up on if present.