Pro tip: spent 4 hours last Saturday chasing a bug that was one stray semicolon in my CSS
I was building my first real page for a friend's dog walking business and the whole layout kept breaking on mobile, so I kept rewriting my media queries over and over. I probably reloaded the browser 60 times and even redid my flexbox from scratch twice before my roommate looked at it for two seconds. There was a semicolon sitting right after a closing bracket in my stylesheet, so the browser was just tossing out everything below that line. I sat there in my kitchen in Akron for maybe 20 minutes just staring at the screen feeling dumb. Has anyone else lost a whole afternoon to one tiny typo like that?