Why the css border radius isnt working?

Question

I gave a border radius to the web code using css. But dont know why its not working! Any one have any solution?
https://code.sololearn.com/WT4op2tvfUmW/?ref=app

Answer 1

You wrote ( 2 em ) it should be ( 2em ) , no space between 2 and em . Spaces matter don't add extras :-)

Answer 2

Thanks.... it helped alot :-) Understood the mistake.