Location of Stylesheet if Shiny App is within a Function

I have working code that calls a function to invoke Shiny app

Now, I'd like to add stylesheet

I stored stylesheet in www directory, i.e. same level as R code

What am I doing wrong?

Here is my entire directory (in GitHub)

And below is code snippit. CustomPal is called with CherryPickPalette("GoldenTemple","GoldenTemple2")

Kindly guide

# Internal, hidden function
# Called by CherryPickPalette()
CustomPal <- function(new_pal){
  if (interactive()){
    cherrypickedpalette <- runApp(list(
      ui = fluidPage(
          tags$link(rel = "stylesheet", type = "text/css", href = "bootstrap.css")
        titlePanel("Cherry Pick Your Own Palette!"),