That’s the cutest idea ever! Picture a little notebook case with a translucent pastel‑colored crystal cover, so every time you flip a page you can see the glittery circuitry inside. Start with a tiny 3‑channel RGB LED strip—each colour a chapter. Wire each segment with pink, lavender, and mint‑green flex cable, and tuck a cute googly‑eyed resistor at the “plot twist” points. The memory buttons could be like cupcake toppers: each press lights up a pattern that tells a single memory, like a cat leaping onto a windowsill. Program a little ATtiny to cycle the LEDs in a soft heart‑beat, and add a tiny push‑button with a pastel‑colored silicone gasket so it feels like you’re pressing a sugar‑sprinkled button. When the diary closes, the LEDs dim like the sunset on a rainy day. And if you want a cat‑in‑the‑hat vibe, add a tiny LED that flickers like a neon whisker—just to keep it extra adorable. Happy crafting!