Refused to apply style from 'http://localhost:63342/app/three-level-menu/try.css' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled code example
Example: stylesheet not loaded because of mime-type
put your .css file in a folder called public
in your app.js file add the following code:
app.use(express.static('public'));