CodePen is a social development environment that allows you to write code in the browser and see the results as you build. It is an online code editor and community for front-end designers and developers to build, test, and discover front-end code using HTML, CSS, and JavaScript.
CodePen 是一个社交开发环境，让你可以在浏览器中编写代码并实时查看构建结果。它是一个面向前端设计师和开发者的在线代码编辑器与社区，用于使用 HTML、CSS 和 JavaScript 构建、测试和发现前端代码。