CSS was first proposed in 1994 by Håkon Wium Lie, a Norwegian computer scientist and web developer.


CSS allows you to separate the presentation of a website from its structure and content, which makes it easier to maintain and update the look and feel of a website.


CSS is used to style and layout web pages, and can be used to create a wide range of visual effects, such as animations, gradients, and responsive design.


CSS has several different versions, the latest version is CSS3, which was first released in 1999 and is still under development.


CSS has a wide range of properties and selectors that can be used to style different elements on a web page, such as text, images, and links.


CSS has several different layout models, such as block, inline and table layout, which can be used to create different types of layouts for web pages.


CSS can be written in a .css file and linked to HTML pages, or it can be written in-line in the HTML pages, or it can be written using JavaScript.


CSS can be used to create responsive web designs that automatically adjust to different screen sizes and resolutions.


CSS has a feature called "media query" which allows to create styles that apply only when certain conditions are met, such as the screen size or resolution.


CSS has a preprocessor language like SASS, LESS and Stylus which adds more functionalities and a more organized way to write css.


CSS has a library called CSS Grid and CSS Flexbox, which allows creating complex and dynamic layout easily.


CSS has a feature called "pseudo-classes" and "pseudo-elements" which allows to select and style certain elements based on their state or position within the document.