background-colorThe background-color CSS property sets the fill color of an element, behind any content and background images or gradients.backgroundBackgroundwidely2015-07-292018-01-29https://drafts.csswg.org/css-backgrounds-3/#background-colorhttps://developer.mozilla.org/docs/Web/CSS/Reference/Properties/background-colorcss.properties.background-colorcss.properties.background-color.transparenthttps://nowyoucanuse.com/features--background-color.html