"Qianfeng PHP-CSS Introduction and Application Video Tutorial" HTML and CSS are the core technologies that make up WEB front-end development, so combined with the previous HTML course, and then learning this CSS course, you will get a better experience. The course content is very well-paced, allowing you to study from start to finish without any stress. Briefly explain some introductory knowledge about CSS. By studying this chapter, you can simply know what CSS is. In fact, this is enough.