The process of developing any web application usually revolves around two main areas: functionality and appearance. The functionality aspect of a web application includes the structure of the site, the behavior of the controls, the user experience, code for securing the application, what happens when the user clicks a button, and so on. The appearance of a site is somewhat more aesthetic, and involves the use of color, images, the layout of pages, and to some extent, the style of code that is rendered to the browser. A successful application will strike a good balance between the two sides, providing a visually pleasant site that is easy to use and to work with for all users, and it’s the balancing act between the two sides where many sites fail. This chapter starts by introducing the fundamental tools available for styling web applications, before introducing the styling capabilities of Visual Web Developer. It goes through the basics of styling individual controls before moving style information into a separate CSS file, and then introduces themes—a new technique for styling pages and sites.