Notifications Page using Elm

I used Elm which is a functional programming language that compiles to Javascript. I tried to extend this challenge by creating a JSON file and fetching the data, the problem is that on click the un-read messages should be changed to read and the styles should change along with the number of notifications at the top.

I have an idea of how I would do this in vanilla Javascript but it's been a real challenge to do this in Elm.

If anyone has any advice on this matter or on the project in general, then I would appreciate it

Thanks