code: function(decl) {
    if (
      decl.prop == 'position' &&
      (decl.value == 'absolute' || decl.value == 'fixed')
    ) {
      decl.parent.each(function(neighbor) {
        if (neighbor.prop == 'float' && neighbor.prop != 'none') {
          neighbor.remove()
        }
      })
    }
  }
docs: 删除多余的 float
  当存在 position: absolute|fixed, display: flex 时删除多余的 float