html,body {
width: 100%;
height: 100%;
user-select: none;//禁止用户选择
box-sizing: border-box;
background: url('./../static/bj@2x.png');
background-repeat: no-repeat;//不平铺
background-size: cover;
z-index: -10;
background-position: 0% 0%; //可以不写
background-attachment: fixed;
}