The other day, someone asked me the following question: “If I understand it right clear float is automatic in most modern browsers right?”
If you’re new to CSS, then it would seem that the answer to this question should be “yes, of course — modern browsers don’t have these types of bugs!” But the necessity to clear floats is not a browser bug; it’s actually, well, more of a CSS feature. And it’s still needed in so-called “modern” browsers (assuming you’re using floats for layout).