📅  最后修改于: 2022-03-11 14:47:30.129000             🧑  作者: Mango
/*This property specifiess how far the background should extend within an element*
Values
the default-value is border-box
content-box : background extends to the edge of the content box
padding-box: background extends to the inside edge of the border
border-box: background extends behind the border
initial : sets property to default value
*/