¥CSS specifications
所有 Web 标准技术（HTML、CSS、JavaScript 等）都在称为规范（或 "specs"）的巨型文档中定义，这些文档由标准组织（例如 W3C、WHATWG、ECMA 或 Khronos）发布，并精确定义了这些技术如何 技术应该发挥作用。
¥All web standards technologies (HTML, CSS, JavaScript, etc.) are defined in giant documents called specifications (or "specs"), which are published by standards organizations (such as the W3C, WHATWG, ECMA, or Khronos) and define precisely how those technologies are supposed to behave.
CSS 也不例外 - 它是由 W3C 内一个名为 CSS 工作组 的小组开发的。该小组由浏览器供应商和其他对 CSS 感兴趣的公司的代表组成。还有其他人，称为特邀专家，充当独立的声音；他们与成员组织没有联系。
¥CSS is no different — it is developed by a group within the W3C called the CSS Working Group. This group is made of representatives of browser vendors and other companies who have an interest in CSS. There are also other people, known as invited experts, who act as independent voices; they are not linked to a member organization.
新的 CSS 功能是由 CSS 工作组开发或指定的 - 有时是因为特定浏览器对拥有某些功能感兴趣，有时是因为 Web 设计者和开发者需要某种功能，有时是因为工作组本身已经确定了一项要求。CSS 不断发展，新功能不断涌现。然而，CSS 的一个关键点是，每个人都非常努力地工作，永远不会以破坏旧网站的方式进行更改。一个建于 2000 年的网站，使用当时有限的 CSS，今天应该仍然可以在浏览器中使用！
¥New CSS features are developed or specified by the CSS Working Group — sometimes because a particular browser is interested in having some capability, other times because web designers and developers are asking for a feature, and sometimes because the Working Group itself has identified a requirement. CSS is constantly developing, with new features becoming available. However, a key thing about CSS is that everyone works very hard to never change things in a way that would break old websites. A website built in 2000, using the limited CSS available then, should still be usable in a browser today!
作为 CSS 的新手，你可能会发现 CSS 规范让人不知所措 - 它们旨在供工程师用来实现对用户代理中功能的支持，而不是供 Web 开发者阅读以理解 CSS。许多经验丰富的开发者更愿意参考 MDN 文档或其他教程。尽管如此，了解这些规范的存在并了解你正在使用的 CSS、浏览器支持（见下文）和规范之间的关系是值得的。
¥As a newcomer to CSS, it is likely that you will find the CSS specs overwhelming — they are intended for engineers to use to implement support for the features in user agents, not for web developers to read to understand CSS. Many experienced developers would much rather refer to MDN documentation or other tutorials. Nevertheless, it is worth knowing that these specs exist and understanding the relationship between the CSS you are using, the browser support (see below), and the specs.