Which technology is used to provide the styling and visuals of a web document written in markup language?

Cascading Style Sheets (CSS) are specifically designed for styling web documents that are written in markup languages like HTML. CSS allows web designers to separate content from presentation, enabling them to apply styles such as colors, fonts, layouts, and spacing systematically across multiple pages of a website. This separation enhances maintenance and keeps the design consistent, making it easier to update the look and feel of a site without altering the underlying HTML structure.

Other technologies listed serve different purposes. JavaScript is primarily used for creating interactive and dynamic content on the web, while HTML (HyperText Markup Language) provides the basic structure of a webpage but doesn't handle the styling aspect. XML (eXtensible Markup Language) is used for data representation and transfer rather than presentation, focusing on structuring data rather than styling it. Thus, CSS is the fundamental technology for achieving the visual aesthetics of web documents.