That one fucking time my text editor so damn high, that it choose to encode my file utf-8 BOM.
I was using Notepad++ because I thought it would just provide a good syntax highlighting, without stabbing me in the back

Seemingly nothing wrong with the code, but it took me, a friend and two teacher almost half an hour to figure out why the css simply wasn't work, even though it was clearly used and worker as intended when embeded in the file.

This was some years ago, so please don't judge me for my editor of choice at that time

Other than that, i simply suck at css and gladly use css frameworks 😅