My first job out of college was writing html/css for email messaging. In the case of webmail you had to contend with the butchery of email clients, email server

My first job out of college was writing html/css for email messaging. In the case of webmail you had to contend with the butchery of email clients, email servers, and the browser. That was when IE7 just came out which had a different box model than IE6. That was the school of hard knocks. After that CSS has been mostly trivial to write cross browser for me. The biggest challenges I would encounter are helpers, like jQuery or frameworks, getting in the way and breaking things.