CSS (Cascading Style Sheets) is a styling language used to describe the layout and presentation of an HTML or XML document. It allows developers to separate the presentation of a website or web application from its content, making it easier to maintain and update the design of the website.
Here’s how CSS works:
- A web browser loads an HTML or XML document and applies any CSS styles that are included in the document or linked to it.
- The CSS styles are applied to the elements in the HTML or XML document, determining how they are displayed on the page.
- CSS styles are made up of selectors, properties, and values. A selector is used to target specific HTML elements, such as a heading, paragraph, or image. Properties are used to specify the layout or visual characteristics of the element, such as its color, font, or position. Values are used to specify the specific value of the property, such as “red” for the color property or “12px” for the font-size property.
- CSS has a cascading nature, meaning that styles can be inherited from parent elements to child elements. This allows developers to define styles for a specific element, and then have those styles applied to all child elements within that element.
- CSS also has a specificity system that determines which styles will be applied to an element. If two styles are conflicting, the browser will apply the style with the most specific selector.
- CSS allows to use media queries that allow to apply different styles depending on the device or screen size.
- With the use of CSS preprocessors (CSS precompilers) like SASS, LESS and STYLUS, developers can use variables, nesting, and other features to make the CSS code more organized, readable and maintainable.
By using CSS, developers can create visually appealing and responsive websites that adapt to different screen sizes and devices, making it easier for users to navigate and interact with the content.