Stick your landings! position: sticky lands in WebKit  |  Web  |  Google Developers

position: sticky is a new way to position elements and is conceptually similar to position: fixed. The difference is that an element with position: sticky behaves like position: relative within its parent, until a given offset threshold is met in the viewport.

Source: Stick your landings! position: sticky lands in WebKit  |  Web  |  Google Developers