background-sizeThe background-size CSS property scales or stretches a background based on the size of the element (with the contain and cover keywords), a length, or percentage.backgroundBackgroundwidely2015-07-292018-01-29https://drafts.csswg.org/css-backgrounds-3/#background-sizehttps://developer.mozilla.org/docs/Web/CSS/Reference/Properties/background-sizecss.properties.background-sizecss.properties.background-size.autocss.properties.background-size.containcss.properties.background-size.covercss.properties.background.background-sizehttps://nowyoucanuse.com/features--background-size.html