Topic
CSS
CSS describes the presentation of documents such as HTML pages. Rules select elements and assign visual properties, including layout, spacing, color, and typography.
At a glance
- Expansion
- Cascading Style Sheets
- Rule components
- Selector and declarations
Overview
CSS describes the presentation of documents such as HTML pages. Rules select elements and assign visual properties, including layout, spacing, color, and typography. The cascade determines how applicable declarations combine when more than one rule targets an element.
Rules and the cascade
Selectors identify which elements a rule affects. Declarations assign property values, and the cascade resolves competing declarations using defined precedence. Understanding that process helps explain why an expected style is not applied.
Responsive presentation
Layout systems and conditional rules let presentation adapt to available space and user preferences. The underlying content still needs meaningful structure so that visual changes do not remove the page's essential information.
Sources and review
MOOR's explanatory text is supported by the following source links.
- CSS reference — MDN Web Docs
- Cascading Style Sheets overview — W3C