A CSS Developer is a web developer who specializes in using Cascading Style Sheets (CSS) to design and layout the visual appearance of websites and web applications. They focus on defining the structure, style, and presentation of HTML elements, including aspects such as colors, fonts, spacing, positioning, and responsiveness. CSS developers are skilled in advanced techniques like CSS Grid, Flexbox, animations, and transitions to create visually appealing, interactive, and responsive user interfaces. They work closely with HTML developers and UI/UX designers to ensure that the front-end design is functional, aesthetically pleasing, and optimized for different screen sizes and devices.