---
id: kb-2026-00069
title: CSS (Cascading Style Sheets)
schema_type: TechArticle
category: computer-science
language: en
confidence: medium
last_verified: '2026-05-28'
created_date: '2026-05-22'
generation_method: ai_structured
derived_from_human_seed: true
conflict_of_interest: none_declared
is_live_document: false
data_period: static
atomic_facts:
  - id: fact-css-1
    statement: >-
      W3C CSS Snapshot 2024 defines CSS as a language for describing the rendering of structured
      documents such as HTML and XML.
    source_title: CSS Snapshot 2024
    source_url: https://www.w3.org/TR/css-2024/
    confidence: medium
  - id: fact-css-2
    statement: MDN describes CSS as the styling language used to style and lay out web pages.
    source_title: 'MDN: What is CSS?'
    source_url: https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/What_is_CSS
    confidence: medium
  - id: fact-css-3
    statement: >-
      CSS Snapshot 2024 explains that modern CSS is modular rather than a single monolithic
      specification.
    source_title: CSS Snapshot 2024
    source_url: https://www.w3.org/TR/css-2024/
    confidence: medium
completeness: 0.86
known_gaps:
  - This compact article intentionally covers a small, source-mapped slice of a broader topic.
disputed_statements: []
primary_sources:
  - title: CSS Snapshot 2024
    type: standard
    year: 2025
    url: https://www.w3.org/TR/css-2024/
    institution: W3C CSS Working Group
  - title: 'MDN: CSS'
    type: documentation
    year: 2026
    url: https://developer.mozilla.org/en-US/docs/Web/CSS
    institution: MDN Web Docs
  - title: 'MDN: What is CSS?'
    type: documentation
    year: 2026
    url: https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/What_is_CSS
    institution: MDN Web Docs
secondary_sources: []
updated: '2026-05-28'
---

## TL;DR

CSS is the web styling language that describes how structured documents are rendered across media.

## Core Explanation

CSS separates presentation from document structure. Its modern standardization model is modular, with individual specifications covering selectors, layout, color, fonts, and other parts of the rendering system.

## Further Reading

- [CSS Snapshot 2024](https://www.w3.org/TR/css-2024/)
- [MDN: CSS](https://developer.mozilla.org/en-US/docs/Web/CSS)
- [MDN: What is CSS?](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/What_is_CSS)