CSS, which stands for Cascading Style Sheets, is a stylesheet language used to control the presentation, layout, and formatting of web documents written in HTML (Hypertext Markup Language). It plays a crucial role in web development by separating the content (HTML) of a web page from its visual representation, allowing developers to define how elements should be displayed on the screen or other media types.
Here are some key points about CSS:
- Styles and Formatting: CSS is used to apply styles, formatting, and visual enhancements to HTML elements. This includes controlling aspects such as fonts, colors, spacing, borders, backgrounds, and positioning of elements on a web page.
- Separation of Concerns: CSS promotes the separation of content (HTML) and presentation (CSS). This separation makes it easier to update the design of a website without having to modify the underlying content and structure.
- Selectors and Properties: CSS uses selectors to target HTML elements and apply styling rules. For example, you can use a selector like
pto target all paragraphs and then specify properties like
colorto set the text color or
marginto control the spacing around paragraphs.
- Cascading and Specificity: The term “cascading” in CSS refers to the order in which styles are applied, with styles from different sources (e.g., external stylesheets, internal styles, inline styles) cascading down and potentially conflicting with each other. CSS also employs specificity rules to determine which styles should take precedence when there are conflicting declarations.
- Media Queries: CSS allows for the creation of responsive web designs by using media queries. These queries enable developers to apply different styles based on factors like screen size, device type, and orientation, ensuring that web pages adapt to various viewing environments.
- CSS Frameworks: Many developers use CSS frameworks (e.g., Bootstrap, Foundation) to streamline the process of designing and structuring web pages. These frameworks provide pre-designed CSS styles and layouts that can be customized to fit the specific needs of a project.
To learn CSS for free go to: web.dev/learn/css