CSS class does not work

Question

The element has a class "bigtext", in which {color: white; font-size: 2em; } but this does not work. Please explain why
https://code.sololearn.com/WnOMbtE4isV2/?ref=app

Answer 1

invalid syntax
remove semicolon after curly braces at .menu-item class

Answer 2

Thank you so much :)