What else is there to know about HTML? You’re well on your way to mastering HTML. In fact, isn’t it about time we move on to CSS and learn how to make all this bland markup look fabulous? Before we do, we need to make sure your HTML is really tight (you know... buttoned up, ship shape, nailed down) and we’re going to do that by getting serious about the way we write our HTML. Don’t get us wrong, you’ve been writing first-class HTML all along, but there’s a few things you can do to help the browser faithfully display your pages and to make sure that little mistakes don’t creep into your markup. What’s in it for you? Pages that display more uniformly across browsers (and even display well on mobile devices and screen readers for the visually impaired), pages that load faster, an....