CSS3, Cascading Style Sheets, are responsible for displaying elements of a document written in HTML5. Separating document structure from its look definition increases its change possibility – depending on the device we can change elements appearance without changing their structure. Comparing to previous specifications, the possibilities offered by CSS3 are huge, and, what is more important, they are supported by most web browsers.

Among many advantages of CSS3 we should mention possibilities of positioning, setting text size, text background or text colour adjusting. Moreover, we can define fluent changes in elements’ appearance or position after an action undertaken by the user, for example clicking an item, or with certain frequency. This enables us to resign from Flash technology, mostly used to create animations.

Thanks to “media queries” we are able to define other style sheets for different devices depending on the screen size available or screen type. Practically it ensures the possibility of creating responsive solutions, that without the need to change the document’s structure will be displayed clearly and in an attractive way on every device having a web browser.