为什么tag $ style产生类型为Closure的错误对象不是子集的？

Question

当我删除tag $ style时，r脚本起作用了，这是我做错了什么？

library(shiny)
library(shinythemes)
#library(shinydashboard)
library(shinyjs)
# library(data.table)

# m <- fread('https://docs.google.com/spreadsheets/d/e/2PACX-1vTXyt7-fA0IghvwpOZw5agYei58qiUHEsH1BHJ_r5wmhsss8LR0KTGy1DjfZjKpgkfR6EBuE1DBt10z/pub?gid=367115990&single=true&output=csv')

ui <- fluidPage(tagList(

windowTitle =    
tags$head(

  tag$style(
  #   HTML(
  #     "
  # .navbar-nav {
  # float: none !important;
  # }
  # .navbar-nav > li:nth-child(6) {
  # float: right;
  # right: 225px;
  # }
  # .navbar-nav > li:nth-child(7) {
  # float: right;
  # right: -60px;
  # }
  # ")
  ),

  tags$link(rel = "shortcut icon", href = "favicon.png"),
  tags$title("Exodus 3:14 ... Seeking Those Seeking HIM"),

  tags$script(type="text/javascript", src = "code.js")),


navbarPage(theme = shinytheme("cerulean"),title = "Literate Aspects",

#---------------> First tabPanel
tabPanel("First",value = "page-nav-second",
         # useShinyjs(),
         # actionButton("remove", "show / hide"),

mainPanel(
  tabsetPanel(id = "tabs",
              tabPanel(id = "M", "M tab",

                       textInput("text", "Text")),

              tabPanel(id = "N", "N tab"),
              tabPanel(id = "W", "W tab")
  )
)
         ),  # end first tabPanel

#---------------> Second
tabPanel("Second",value = "page-nav-second"),  # end second tabPanel 

#---------------> Third tabPanel
tabPanel("Third",value = "page-nav-third"),  # end third tabPanel

#---------------> Fourth tabPanel
tabPanel("Fourth",value = "page-nav-fourth"),  # end fourth tabPanel

#---------------> Fifth tabPanel
tabPanel("Fifth",value = "page-nav-fifth"),  # end fifth tabPanel

#---------------> Sixth tabPanel
tabPanel("Sixth", value="page-nav-sixth"),  # end sixth tabPanel

#---------------> Seventh tabPanel
tabPanel("Seventh", value="page-nav-seventh")  # end seventh tabPanel
)
)
)