背景图片撑满全屏

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