> 1. Many early web engines used `display: content-box`. So the padding was actually considered to be outside of the box itself. IIRC this was actually the spe

> 1. Many early web engines used `display: content-box`. So the padding was actually considered to be outside of the box itself. IIRC this was actually the spec, and IE decided to ignore it and do something saner, while the box-sizing attribute to pick what you wanted came later. Designing for content-box and IE displaying using border-box (or whatever it did) was one of the reasons it got the nickname "internet exploder" - everything ended up positioned or sized wrong. Until box-sizing came along, it was common to use various hacks / bugs in the browsers' CSS parsers to make certain rules only apply to certain browsers to fix this.