Arduino Birthday Surprise Box (LDR + Buzzer + 3 LEDs)

They opened the gift box and the box started singing! An **LDR** hidden inside notices the light when the lid opens; the **buzzer** plays "Happy Birthday" and **3 LEDs** light up with the notes. When the song ends, the LEDs flicker like birthday candles. Make it as a **gift** for someone you love: it runs on batteries and goes quiet when the lid closes.