CSS (Cascading Style Sheets) is a style sheet language used for describing the visual presentation of web pages. It is used to control the layout and appearance of HTML (Hypertext Markup Language) and XML (Extensible Markup Language) documents.
CSS is used to define the styles for various HTML elements, such as fonts, colors, backgrounds, borders, and spacing. It allows designers and developers to separate the content of a web page from its presentation, making it easier to maintain and update the appearance of the website.
CSS works by applying rules to HTML elements. A CSS rule consists of a selector, which specifies the element or elements to which the rule applies, and a declaration block, which contains one or more properties and values that define the style of the element.
For example, the following CSS rule sets the font size of all paragraphs to 16 pixels:
p {
font-size: 16px;
}
CSS also allows developers to use advanced layout techniques, such as flexbox and grid, to create complex, responsive layouts that adjust to different screen sizes and devices.
CSS is a critical part of web development and is used by developers and designers around the world to create beautiful, engaging websites. It is supported by all modern web browsers and is constantly evolving to support new design trends and techniques.