How to centralize title that is in navbarPage

I would like to center the name NAMETOOL which is in navbarPage. See in the attached image that the title is well to the left. I would therefore like to leave it more in the center.

Code executable below:

library(shiny)
library(shinythemes)

ui <- shiny::navbarPage(theme = shinytheme("flatly"),
                        title="NAMETOOL", collapsible = TRUE, selected = "HOME", 
                        
                        
                        tags$head(
                
                          tags$style(HTML("
                          div.container-fluid { padding:0; } /* Remove padding here */
                           .navbar { margin-bottom: 0; }"
                          ))
                        ),
                        
                        tabPanel("HOME",
                                 icon = icon("home"),
                                 div(
                                   style =
                                     "height: 315x; background-color: rgba(0,0,0); width: 100%; position: relative; right:0;padding:0;",
                                   
                                   tags$iframe(width="853", height="480", src="", 
                   
                                               frameborder="0", allow="accelerometer; autoplay; encrypted-media; gyroscope; 
                                               picture-in-picture", allowfullscreen=NA)
                                 ),style="text-align:center",
                                 
                                   div(
                                     style = "width: 80%; margin: auto;",
                                     
                                     h1(HTML("<u> WELCOME <b>NAME</b> </u>"),
                                        style="text-align:center; color: white;"),
                                     br(),
                                     tags$style(".navbar {margin-bottom: 0;}"))))





server <- function(input, output,session) {
  
  
}

shinyApp(ui = ui, server = server)

Output

enter image description here