Develop a detailed design concept for an interactive, dynamic visual sequencer that combines a countdown timer with generative art scenes, functioning as a playlist of visual segments. Each segment should represent a unique, generative pattern or scene, with the countdown timer visually integrated to reflect the sequence's progress. Emphasize the creation of smooth, fluid transitions between scenes, such as crossfades, to craft a seamless and immersive visual narrative. The patterns within the scenes must be modular, composable, and remixable, allowing for flexible manipulation similar to remixing parts in a visual or animation context, inspired by the principles of de9 transitions but tailored for animation loops rather than sonic elements. The overall aesthetic should merge qualities of a VJ performance tool with a Pomodoro timer, drawing inspiration from the Endel x Plastickman aesthetic, and should utilize a neon-dusk color palette to evoke a vibrant yet subdued mood.