What is CSS and what features does it offer?

Cascading Style Sheets (CSS) is a style sheet language that is used to style and format the appearance of HTML or XML documents. CSS allows content and presentation to be separated by allowing developers to define the layout, colors, fonts, and other visual properties of a web page without changing the HTML code themselves. This makes web pages easier to maintain, consistently, and customize. Here are some key concepts and features of CSS:

1. selectors: CSS uses selectors to select HTML elements to apply styles to. For example, the “p” selector can be applied to all paragraphs in a document.
2. Features: CSS defines various properties that influence the appearance of elements, such as “color” for the text color, “font-size” for the font size, and “margin” for the space around an element.
3. Values: Each property in CSS can have one or more values. For example, the “color” property may have the value “red” or “#FF0000.”
4. declarations: In CSS, styles are defined in so-called declarations. A declaration consists of a property and a value, separated by a colon and terminated by a semicolon. For example: “color: blue;”.
5. Cascading: “Cascading” in CSS stands for the hierarchy in which styles are applied to elements. CSS rules can come from various sources, such as external style sheets, internal styles, or inline styles, and they are applied in a specific order, involving priorities and specificity.
6. Selectors and combinators: CSS provides various selectors and combinators to select more specific or comprehensive elements. For example, you can use the class selector (.class) to select all elements with a specific CSS class.
7. Media queries: CSS makes it possible to adjust the layout and design based on the characteristics of the display device, such as screen size, resolution, and orientation.
8. Pseudo-classes and pseudo-elements: With pseudo-classes (such as:hover for the mouse pointer) and pseudo-elements (e.g.: :before and: :after), you can stylize specific states or parts of elements.
9. External style sheets: It is possible to store CSS rules in external style sheets files, which can then be used on multiple pages on a website. This promotes consistency and maintainability of the design.

CSS is a fundamental part of modern web design and makes it possible to create appealing and well-designed websites. Developers and designers use CSS to customize the look of web pages and ensure that they display correctly on various screen sizes and devices. CSS is constantly being developed to meet the requirements of modern web design.