Sums up most, if not all, of the image replacement techniques currently in use
If you've mastered floating columns, the other tricky piece to the puzzle and one that is heavily used, is floated navigation. The web-standards-lovin' folk love their unordered lists of navigation and there are a myriad of ways to style them up.
Like video games of yore, packing multiple images into one single image has become a popular technique to solve a couple problems. The first is CSS-based rollovers. More recently, it's been proven to be advantageous to combine multiple images — in particular background images used in image replacement techniques — into a single file. This reduces the number of requests your browser has to make, improving the time required to download all files from your server.
Of course, there's always more to learn and if you think there's a technique that you think is especially important for the beginner, be sure to add it to the comments.99热这里只有精品国产，免费99精品国产自在现线，99国产这里有精品视频