sass切换主题

@mixin theme {
  color: #fff;
  background-color: #000;
  [data-theme="theme1"] & {
    color: #f00;
    background-color: antiquewhite;
  }
  [data-theme="theme2"] & {
    color: green;
    background-color: aqua;
  }
  [data-theme="theme3"] & {
    color: #f0f;
    background-color: brown;
  }
}
  changeTheme (theme) {
      window.document.documentElement.setAttribute('data-theme', theme)
    }