Touch Grass Timer

I'm making a website that tells you to take a break from your screen after a set amount of time.(user can choose but default=25 mins) You'll need it running on your browser but you can switch tabs/ minimize the screen if you're working on something else. It plays a notification noise and has a pop-up with a custom message of your choice that will tell you to take a break from the screen(Respectfully, touch grass). I made this for my seven-year-old cousin because, RESPECTFULLY, she needs to get off her iPad. Sadly, she's not on Stardance to see what she inspired me to do. But to my cousin: even though you are very annoying(and I only babysit you because you always bring your cat), thank you :)