background-position-x & background-position-y

CSS longhand properties to define x or y positions separately.

CSS background-position edge offsets

Allows CSS background images to be positioned relative to the specified edge using the 3 to 4 value syntax. For example: `background-position: right 5px bottom 5px;` for positioning 5px from the bottom-right corner.

CSS3 object-fit/object-position

Method of specifying how an object (image or video) should fit inside its box. object-fit options include "contain" (fit according to aspect ratio), "fill" (stretches object to fill) and "cover" (overflows box but maintains ratio), where object-position allows the object to be repositioned like background-image does.

css property: background-position-x: side-relative values (such as `bottom 10%`)