The background-position-x CSS property sets the initial horizontal position, relative to the background position layer defined by background-origin for each defined background image. For more information, see the background-position property, which has been widely supported.
The column-fill CSS property controls how contents are partitioned into columns. Contents are either balanced, which means that contents in all columns will have the same height or, when using auto, just take up the room the content needs.
A media query consists of an optional media type and zero or more expressions that limit the style sheets' scope by using media features, such as width, height, and color. Media queries, added in CSS3, let the presentation of content be tailored to a specific range of output devices without having to change the content itself.