CSS (Cascading Style Sheets) is a stylesheet language used to control the presentation, layout, and styling of HTML documents. It allows web developers to apply styles such as colors, fonts, spacing, and positioning to elements on a webpage.

Key Features of CSS:

1. Separation of Content & Design – CSS separates structure (HTML) from presentation, making websites easier to maintain.
2. Selectors & Rules – CSS applies styles using selectors (e.g., elements, classes, IDs) and rules (e.g., color: red;).
3. Cascading & Specificity – Rules are applied based on hierarchy and specificity.
4. Box Model – Defines how elements are displayed and spaced.
5. Responsive Design – CSS supports media queries for mobile-friendly layouts.

CSS Syntax Example: