Can anyone tell what is the error

Question

Please
https://code.sololearn.com/WhlBH0hKXEfv/?ref=app

Answer 1

The error is that your code is missing. :)
You never defined in Javascript, what the changeColor function is supposed to do, but you reference it in the HTML event handlers.

Answer 2

You've didn't written css and js code.

Answer 3

You need to style your button tags, use button selector in the css tab

Answer 4

Try, button {
width: 20%;
height: 5vh;
}