CSS

Abbreviation · Development

Definitions

  1. CSS, or Cascading Style Sheets, is the language used to describe the presentation and visual formatting of HTML documents. While HTML defines the structure and content of a web page, CSS controls how that content looks: colors, fonts, spacing, layout, animations, and responsive behavior across different screen sizes. The 'cascading' in CSS refers to the system of rules that determines which styles take precedence when multiple rules apply to the same element, based on specificity, source order, and inheritance. CSS selectors target elements by tag name, class, ID, attributes, and pseudo-classes. Modern CSS includes powerful layout systems like Flexbox for one-dimensional layouts and CSS Grid for two-dimensional layouts, replacing older techniques like floats and table-based layouts. CSS custom properties (variables), media queries for responsive design, transitions, animations, and container queries enable rich, adaptive user interfaces. Preprocessors like Sass and Less extend CSS with variables, nesting, and mixins, while methodologies like BEM and CSS Modules help manage styles at scale in large applications.

    In plain English: The language that controls how websites look: colors, fonts, spacing, and layout. HTML is the skeleton, CSS is the skin and clothes.

    Example: "CSS is easy. Until you try to center a div. Then you question your entire career."

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