Responsive Rest Countries using HTML, CSS, JAVASCRIPT and SASS

I don't know if I did great or what, I'm fairly new with JavaScript so I am happy that I finished this website though I have problems with the error handling of this page, its error message prints something that I don't manually throw. I've also had a hard time to think about how I can show the loading spinner while awaiting for the response from the web server Anyway, If you guys have suggestions feel free to comment anything, any comments will be entertained. Godbless.